Uwell Caliburn G3 vs XROS 4: Which Pod Kit?
Only got a minute?
- Caliburn G3 is the simple one. Draw activated, power adjusted for you, side fill, and a flavour-first mouth-to-lung draw. The Caliburn G3 Lite is the version we stock and it keeps the same character in a slimmer body.
- XROS 4 is the adjustable one. The Vaporesso XROS 4 gives you three selectable power levels, a proper airflow slider, a battery display and quick-change pods, so you can tune the draw rather than accept it.
- Pods decide the running cost. Both systems build the coil into the pod, so you replace the whole thing. XROS pods use Corex mesh, refined again in the 3.0 generation.
- Both are nic salt kits first. A 50/50 or 60/40 liquid at 10mg to 20mg is the sweet spot for either. Neither is built for thick 70/30 shortfills.
- Quick verdict: new vapers and flavour chasers take the Caliburn, tinkerers and heavier all-day users take the XROS 4. Browse both in pod kits.
What separates these two kits
Both devices sit in the same part of the market. They are pocket-sized refillable pod kits, both mouth-to-lung, both aimed at people who have moved on from cigarettes or from the big-puff kits that replaced disposables. On paper they look near identical. In the hand they feel like they were designed by people with opposite priorities.
Uwell built the Caliburn G3 around one idea: get out of the way and let the flavour through. There is very little to set. You fill the pod, you draw, the device works out how much power to send and delivers a consistent hit until the battery gets low. Vaporesso went the other way with the XROS 4 and handed you the controls. Wattage, airflow and a display to see what you are doing, all on a device you can still lose in a jacket pocket.
Neither approach is wrong. The question is whether you want a device that makes decisions for you or one you can dial in. If you are still weighing up formats entirely, our guide to the best pod kits for beginners in the UK covers the wider field.
Design, build and how they feel to carry
The Caliburn G3 is deliberately plain. A slim rectangle with rounded corners, a matte finish that does not show fingerprints, and almost no branding. It disappears in a pocket and it does not look like a gadget. The trade-off is that it looks like what it is: a tool. There is no screen on the standard G3, and on the Lite version the controls are stripped back even further.
The XROS 4 is the more polished object. Smoother edges, a glossier shell, a small lighting effect on some finishes and a readable display panel. It feels a little more like a piece of consumer electronics and a little less like a vape. It is also slightly wider because of the airflow slider and the screen, which matters if you wear tight jeans and not at all if you carry a bag.
Durability is close. Both use a plastic and alloy shell that will survive being dropped on a pavement once or twice. The G3 has fewer moving parts, which is one fewer thing to break. The XROS 4 has a sliding airflow control on the body, and sliders are always the first thing to get gritty in a pocket full of keys.
Power, airflow and how they actually vape
This is where the two kits genuinely diverge. The Caliburn G3 reads the pod it is fitted with and sets the power to suit it, then holds that output steady. What you get is a warm, even, tight mouth-to-lung draw that tastes the same on the first puff of the day as it does on the fortieth. For an ex-smoker that consistency is worth more than any feature list, because a cigarette never needed configuring either.
The XROS 4 lets you choose. Wind the wattage down and you get a cooler, longer draw that stretches the liquid further. Wind it up and the vapour gets warmer and denser. The airflow slider does the other half of the job, taking the draw from cigarette-tight to something close to a restricted direct lung. If you like a loose airy draw on a menthol and a tight warm one on a tobacco, only one of these devices will give you both.
Flavour honours go to the Caliburn by a small margin on a like-for-like fresh pod, mostly because Uwell has tuned the whole system around a single draw style. The XROS 4 catches up quickly once you have found your settings, and it stays better across a wider range of liquids. If you are not sure which draw style suits you, read MTL vs DTL inhalation styles before you spend anything.
20mg
UK legal maximum nicotine strength, and what most pod users start on
50/50
PG/VG ratio both kits are built for
USB-C
charging on both, though the Caliburn does not include a cable
Pods, coils and what they cost to run
The kit is a one-off. The pods are forever, and they are where the real difference in cost lives. Both systems put the coil inside the pod, so when the coil is spent you replace the whole thing rather than fiddling with a separate head.
Caliburn G3 pods are side-filled through a simple silicone plug and click straight into place. Filling is quick and the pod seats squarely every time. Pod life is decent rather than exceptional, and sweet or dark fruit liquids will shorten it as they will on any mesh coil. Uwell also sells Caliburn G and G2 replacement coils for the older devices in the same family, which is worth knowing if you own more than one Caliburn.
The XROS side runs on Vaporesso’s Corex mesh. The XROS Corex 3.0 replacement pods are the current generation, with a refined mesh structure for better flavour accuracy. The older Corex 2.0 pods still fit the XROS range if you want an alternative. Across a month of daily use, some vapers report getting more out of a four pack of XROS pods than out of the equivalent Caliburn pack.
| Pod system | Fill method | Resistance choice | Typical pod life |
|---|---|---|---|
| Caliburn G3 pods | Side fill, silicone plug | Narrow, matched to the kit | Around a week on fruit liquids |
| XROS Corex 3.0 pods | Top fill, magnetic seat | Several options across the range | Noticeably longer on the same liquid |
| XROS Corex 2.0 pods | Top fill, magnetic seat | Still sold across the Xros range | Good, still widely stocked |
Pod life varies enormously with liquid. Dark fruits, sweeteners and custards caramelise on mesh and will halve the figures above whichever kit you own.
Battery life and charging
Neither of these is a mod, so nobody should expect two days of heavy use. What they both offer is enough capacity to get a normal vaper from morning to night, plus USB-C charging fast enough that a top-up over a lunch break puts you back in business.
The Caliburn G3 comfortably covers a full day for moderate use. Because the device manages its own output, it does not waste charge pushing more power than the pod needs. The G3 Lite at 1200mah actually carries more capacity than several kits in the same size class, which is the main reason it has stayed popular.
The XROS 4 actually holds slightly less, at 1000mAh against the G3 Lite’s 1200mAh, but its screen tells you exactly how much is left, which sounds minor until you have been caught out by a device that only has three battery lights. Heavier vapers and anyone running higher wattage settings will feel the benefit. If you want the biggest battery in the family, the XROS 5 Mini at 1500mah is the step up, and the XROS 4 Nano squeezes 1350mah into a smaller shell.
Light to moderate vaper
The Caliburn G3 will see out a working day on one charge. Fewer settings also means fewer ways to accidentally drain it.
All-day heavy vaper
The XROS 4 holds more and shows the exact percentage, so you can drop to a lower power level to stretch the last 20% instead of guessing.
Which e-liquids suit each kit
Both kits run best on nicotine salts. Salts are smoother at high strength, they wick well through a small mesh coil and they give the quick nicotine hit that ex-smokers are after. A 10mg salt suits a light to moderate smoker, 20mg suits a twenty-a-day habit, and 20mg is the UK legal maximum so there is nothing above it to chase. Browse the nic salt range or the wider 10ml e-liquid section.
Freebase 50/50 at 3mg to 12mg works in both too, and gives a firmer throat hit if that is what you miss. What neither kit wants is a thick 70/30 shortfill. High VG liquid wicks too slowly through these coils and you will taste the burn within a day. If you are unsure what strength to land on, our guide to how much nicotine you should vape walks through it, and which pod kit works best with nic salts covers the hardware side.
One practical difference: the XROS 4’s power levels mean a liquid that tastes slightly off at stock settings can often be rescued by dropping a level. On the Caliburn, a liquid either suits the device or it does not. That flexibility is the strongest argument for the XROS if you like switching flavours often.
Setting up a new pod kit properly
Most complaints about either device trace back to the first ten minutes of ownership. Do these four things and a pod will last as long as it is supposed to.
- 1
Charge it fully before the first vape. Both kits ship part charged. Starting from full gives you an honest sense of the real battery life and avoids a low-power draw that tastes weak and makes you think the pod is faulty.
- 2
Fill slowly and leave room for air. Fill to just below the top mark, not to the brim. Overfilling is the single biggest cause of gurgling and leaking. Our guide to filling a pod kit correctly has the detail.
- 3
Let it sit for five minutes. The cotton inside a new pod needs time to soak. Fit the pod, put the kit down, make a cup of tea. Skipping this is how people burn a brand new pod on puff one.
- 4
Start low on the XROS, start plain on the Caliburn. On the XROS 4, begin on the lowest power level and work up until the flavour is right. On the Caliburn there is nothing to set, so begin with a light fruit or menthol to learn what a healthy pod tastes like. If anything goes wrong later, how to stop e-liquid leaks covers the usual culprits.
Head to head: which one should you buy
Neither kit is a mistake. The right answer depends entirely on how much involvement you want in your own vaping.
| What matters to you | Caliburn G3 | XROS 4 |
|---|---|---|
| Ease of use | Draw and go, nothing to set | Needs a few minutes to dial in |
| Flavour out of the box | Excellent, tuned for one draw style | Very good, better once adjusted |
| Airflow control | Dual airflow, MTL to restricted DTL | Slider, tight MTL to restricted DTL |
| Wattage control | Automatic | Three power levels, up to 16W |
| Battery | Full day for moderate use | Slightly less, but with a battery readout |
| Running cost | Fair | Often better with Corex pods |
| Best suited to | New vapers, ex-smokers, flavour purists | Tinkerers, heavy users, flavour switchers |
Buy the Caliburn G3 if you want a device that behaves the same way every single day and you have no interest in settings. It is the better first refillable kit and the better recommendation for someone who has just come off cigarettes or off a big-puff kit. The Caliburn GK2 and the Caliburn A3S are smaller siblings worth a look if pocket size is the priority.
Buy the XROS 4 if you like adjusting things, switch flavours regularly, or vape enough that pod life and battery percentage genuinely matter. The XROS 4 Mini is the same idea in a smaller body if you want the Vaporesso pod ecosystem without the extra bulk, and our guide to the best Vaporesso XROS to buy compares the whole line.
If you are coming from a prefilled system and are not sure you want to refill at all, our prefilled pod kit buying guide, the comparison of 4-in-1 versus standard pod kits and the notes on prefilled pod e-liquid compatibility are worth reading first. Refilling is cheaper per ml and it stays cheaper once the Vaping Products Duty arrives on 1 October 2026 at £2.20 per 10ml plus VAT, because the duty lands on the liquid rather than the device.
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Quick answers
Which has better flavour, the Caliburn G3 or the XROS 4?
On a fresh pod with the same liquid, the Caliburn G3 edges it, because Uwell tuned the whole device around one draw style. The XROS 4 matches it once you have set the wattage and airflow to suit the liquid, and it holds up better across a wider range of flavours.
Are the pods interchangeable between the two kits?
No. Caliburn pods only fit Caliburn devices and XROS Corex pods only fit the XROS range. Check the pod your device takes before you order, because the two systems look similar in a photograph.
Can I use shortfill e-liquid in either of them?
Only if it is 50/50 or 60/40. A 70/30 shortfill is too thick for these coils and will wick too slowly, which burns the pod. Stick to nic salts or 50/50 freebase.
Which is better value over a year?
Usually the XROS 4, because the Corex pods tend to last longer before the flavour drops off, and pods are the recurring cost. The gap is small for a light vaper and grows the more you use the device.
I am switching from a big-puff kit. Which suits me?
The Caliburn G3. A big-puff kit asks nothing of you, and the Caliburn is the closest refillable equivalent. Pair it with a 20mg nic salt in a flavour close to the one you were using.
Is there a version of either with a bigger battery?
Yes. The Caliburn G3 Lite carries 1200mah, the XROS 4 Nano carries 1350mah and the XROS 5 Mini carries 1500mah. All three use the same pods as their standard siblings.
