Ask ten vapers which pod kit line rules the refillable world and you will hear two names, over and over: Vaporesso XROS and Uwell Caliburn. Both lines have been around for years, both have huge pod ranges, and both now sit at the top of their game with a current flagship. So this is not a comparison of two random kits. It is a straight fight between the Vaporesso XROS 6 and the Uwell Caliburn G5, the two devices these brands would each pick to represent them today.
That matters, because older comparisons still floating around the web pair the XROS 4 or XROS 5 against the Caliburn G3, and both lines have moved on since. The XROS 6 brings a bigger battery and a new airflow system. The Caliburn G5 brings a bigger battery too, a new long-life pod, and a control system that works by tapping the device. If you are buying now, these are the two to judge.
One note before the detail: both kits are refillable pod systems, which means you buy e-liquid in 10ml bottles and fill the pod yourself. If you are still weighing that format against disposables, our guide to the best disposable vapes lays out the trade-offs. The short version is that refillables cost far less per week once you own the kit, and both of these kits are built for nicotine salts at typical UK and US strengths.
The short answer, before the detail
If you want the one-line version, here it is: buy the XROS 6 if battery life and fast charging matter most to you, and buy the Caliburn G5 if flavour and feel matter most. That is not a cop-out. Across five scored rounds below, the two kits finish dead level, and the tiebreaker is genuinely about what you personally value. Read the rounds that match your priorities and the winner will pick itself.
Head to head on paper
Here is the spec sheet that actually affects daily vaping, cross-checked against manufacturer listings and current retailer specs. UK pods are 2ml under TPD rules, while US versions of both kits use 3ml pods.
| Spec | Vaporesso XROS 6 | Uwell Caliburn G5 |
|---|---|---|
| Battery | 1,800mAh | 1,600mAh |
| Max output | 30W | 35W |
| Charging | USB-C, up to 3A | USB-C, 5V/2A |
| Screen | 0.88 inch TFT colour | 0.85 inch HD colour |
| Pod platform | XROS series pods, 0.4 to 1.2 ohm | GPP pods, 0.4 to 1.2 ohm |
| Pod capacity | 2ml UK, 3ml elsewhere | 2ml UK, 3ml elsewhere |
| Filling | Top fill | Top or side fill, pod dependent |
| Airflow | VENTURI side slider | Stepless side slider |
| Activation | Button or draw | Button or draw |
| Power modes | Eco, Normal, Power | Waves, Storm |
| Pods in the box | 2 (0.6 and 0.8 ohm) | 3 (0.4, 0.6, and 0.6 Alpha) |
| Size | 122 x 24.5 x 14.5mm | About 116 x 28.9 x 16.8mm |
| Weight | Around 65g | Around 65g |
Two things jump out immediately. The XROS 6 has the bigger battery, and the Caliburn G5 has the higher wattage ceiling and an extra pod in the box. Neither advantage is as simple as it looks, which is where the rounds come in.
Round 1: Flavour
This is the round Caliburn built its reputation on, and the G5 defends it well. The PRO-FOCS 4.0 coil system delivers a warm, full flavour on the 0.6 ohm pod, and the soft-touch TPU mouthpiece is a small detail that genuinely improves the feel of every draw. Dessert and tobacco flavours come through rounded rather than sharp, and the flavour holds up well as the pod ages.
The XROS 6 is no slouch. Its COREX 3.0 mesh pods are consistent, clean, and arguably better at keeping brighter fruit flavours crisp. Where it loses a fraction is in richness: on the same liquid, the Caliburn tastes a touch fuller, especially in the first half of a pod’s life. Long-term testers of both lines also report that XROS pods fade more gradually, so the XROS claws some ground back over a full pod’s lifespan. But judged purely on flavour at its best, Caliburn takes it.
Score: Caliburn 9, XROS 8.
Round 2: Battery and charging
Now the XROS 6 hits back, hard. Its 1,800mAh cell is the largest ever fitted to a full-size XROS, up from 1,500mAh on the XROS 5, and it shows. A mouth-to-lung vaper on the 0.8 ohm pod will comfortably get through a full day and well into the next, while heavier users still get a full day without hunting for a charger. The Caliburn G5’s 1,600mAh cell is also a step up for its line, and Uwell quotes up to six days of light use, but in realistic daily use the XROS lasts longer between charges.
Charging widens the gap further. The XROS 6 charges over USB-C at up to 3A, and Vaporesso claims roughly 50 percent in about ten minutes with a suitable charger. The Caliburn G5 charges at 5V/2A, which is respectable but plainly slower. If you charge overnight, this barely matters. If you top up between outings, it matters a lot.
Score: XROS 9, Caliburn 8.
Round 3: Pods, leaks and refilling
Both pod platforms are excellent, and both are shared across their wider ranges, which is a big deal for long-term ownership. Every XROS pod fits every XROS device, so if you already own an older XROS, your spares carry over. Likewise, GPP pods fit the G3, G4 and G5 lines, so Caliburn owners are equally well covered. Neither brand locks you into one device’s pods.
On refilling, the XROS 6 uses top-fill pods, which means you pop the mouthpiece section and fill without removing the pod. The Caliburn G5’s pods vary by version, with top-fill and side-fill options in the range, and both work fine with a standard 10ml bottle nib. On leaks, the XROS 6 uses SSS 2.0 sealing and the Caliburn G5 uses Uwell’s U2 anti-leak construction, and both are reliable in a pocket. Neither is perfect, and a worn pod will eventually weep on either system, but neither has a leak problem worth worrying about.
The Caliburn’s edge here is the box contents: three pods instead of two, including the new 0.6 ohm GPP Alpha pod, which Uwell positions as a longer-life option. That extra pod is worth real money, and it tips an otherwise even round into a draw.
Score: XROS 9, Caliburn 9.
Round 4: Daily use and controls
This round is about how the kit feels to live with, and it splits the two philosophies cleanly. The XROS 6 gives you a button, a clear 0.88 inch screen showing battery percentage, power mode and puff count, and three modes to choose from. It also has a genuinely useful 60-second Smart Prime countdown that tells you when a fresh pod is saturated and ready, which is a small kindness to new vapers that most kits skip.
The Caliburn G5 answers with Smart Triple-Tap control: tap the device to switch modes, themes and brightness without hunting through menus. Its Waves mode gives a smoother draw and its Storm mode gives a bolder one, and the colour-matched screen themes are a nice touch. The trade-off is that triple-tap controls take a day or two to learn, and some users report the odd mis-tap. The XROS screen is more immediately obvious, while the Caliburn feels more polished once learned. On balance, the Caliburn’s comfort, mouthpiece and clever controls just edge it.
Score: Caliburn 9, XROS 8.
Round 5: Running costs
Refillable kits pay for themselves against disposables, but the two systems are not identical on running costs. Here is a realistic monthly maths exercise, using stated assumptions so you can adjust it to your own prices. Kit prices vary by retailer, but at the time of writing the two kits sit in the same rough bracket, around the mid-20s in pounds or low-30s in dollars, so the kit price is not the deciding factor. The ongoing cost is pods plus liquid.
| Monthly cost | Vaporesso XROS 6 | Uwell Caliburn G5 |
|---|---|---|
| Pods used (1 per week) | 4 pods | 4 pods |
| Pod cost, assumed £9 per pack of 4 | £9 | £9 |
| E-liquid, 10ml bottle every 2 days | About 15 bottles | About 15 bottles |
| Liquid cost, assumed £3 per 10ml | £45 | £45 |
| Monthly total, assumptions stated | About £54 | About £54 |
| First month, including kit | About £79 | About £79 |
The totals land in the same place because both systems use the same liquid and similar pod pricing. Where they differ is pod lifespan: if the GPP Alpha pod genuinely lasts longer, as Uwell claims, Caliburn owners may stretch to three pods a month instead of four, saving a couple of pounds. Conversely, XROS pods are stocked almost everywhere, which makes bargain hunting easier. Either way, the honest answer is that running costs will not decide this comparison. For a deeper breakdown of what juice actually costs, see our juice price guide.
One cost that does differ is the UK vape duty angle. E-liquid prices in the UK now include duty, and the rules keep shifting, so it pays to understand what you are actually paying for. Our explainer on the UK vape duty breaks down the per-10ml charge and how it feeds into bottle prices.
Score: XROS 9, Caliburn 8. The XROS takes this round on pod availability and bargain hunting, not on sticker price.
Who should buy which
Forget the totals for a moment and match the kit to the vaper.
Buy the Vaporesso XROS 6 if: you vape heavily and hate charging, you want the fastest top-ups, you already own XROS pods, or you like a clear screen that tells you exactly what is going on. It is also the safer pick if you are buying your first refillable kit and want the most forgiving experience, thanks to the Smart Prime timer and the simple mode system.
Buy the Uwell Caliburn G5 if: flavour is your top priority, you like a softer mouthpiece and a more premium-feeling device, you want three pods in the box, or you enjoy a bit of customisation in how the device looks and behaves. It is also the pick if you want the higher 35W ceiling for restricted direct-lung vaping on the 0.4 ohm pod.
If you are switching from smoking, either kit works, and the choice matters less than the liquid strength you pick. For context on how vaping stacks up against smoking in general, our piece on smoking versus vaping covers the evidence in plain terms.
The verdict
| Round | Vaporesso XROS 6 | Uwell Caliburn G5 |
|---|---|---|
| Flavour | 8 | 9 |
| Battery and charging | 9 | 8 |
| Pods, leaks and refilling | 9 | 9 |
| Daily use and controls | 8 | 9 |
| Running costs | 9 | 8 |
| Total | 43 | 43 |
A draw is not a dodge here, it is the honest result. These are the two best refillable pod kits of their type, and neither beats the other outright. So here is the tiebreaker, in the form of one question: when your kit is in your hand at the end of a long day, what do you notice first, the flavour or the battery bar? If the answer is flavour, buy the Caliburn G5. If the answer is the battery bar, buy the XROS 6. And if you still cannot decide, buy the XROS 6, because its battery and charging edge is the thing you will feel every single day, while the flavour gap is one you will only notice when comparing the two side by side.
Either way, you are not making a mistake. Both kits are a huge step up from disposables on cost, and both will still be easy to buy pods for in a year’s time, which is more than can be said for most of the pod kits that came and went in the last few years. If you want a sense of how the wider market looks, the Pulse X review shows what the disposable end of the market is doing, and the SBX vape review covers a very different kind of device altogether.
Quick answers
Can I use my old XROS pods in the XROS 6?
Yes. The XROS 6 takes the full XROS pod range, from 0.4 to 1.2 ohm, so pods from older XROS devices carry over.
Can I use G3 or G4 pods in the Caliburn G5?
Yes. The G5 uses the GPP platform, which is shared with the G3 and G4 lines, so older GPP pods fit.
Which kit is better for a heavy vaper?
The XROS 6, thanks to its larger 1,800mAh battery and faster 3A charging. Heavy users will feel that difference daily.
Which kit gives better flavour?
The Caliburn G5, by a small margin, particularly on dessert and tobacco liquids through the 0.6 ohm pod.
Are both kits legal in the UK and the US?
Both are refillable pod kits sold widely in both markets, but rules on nicotine strength and pod size differ by country, so check local rules before ordering. The FDA authorised list is the reference point for what holds marketing authorisation in the US.