The HTC One M9 and Samsung Galaxy S6 are the two most talked about smartphones right now ahead of their expected unveilings from Mobile World Congress on 1 March.

Both HTC and Samsung have been teasing photos and videos about their devices to build up the big reveal. While Samsung could be called the king of Android, HTC is getting plenty of attention too. Could the HTC One M9 be the device that beats Samsung's next flagship?

We've rounded up every official teaser, rumour and tidbit on the new handsets to see what we can expect. Which will you go for?

Designed to dazzle

The Samsung Galaxy S6 is expected to ditch the plastic of its predecessors in favour of an all-metal unibody encased in glass, back and front. This is part of its back to the drawing board approach it's calling Project Zero.

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Samsung Norway

Then there's the Galaxy S6 edge with its wrap-around screen which should make for a bezel-free effect on the sides. From Samsung's official teasers this looks great, but whether looks alone will draw people to pay more is another matter.

HTC has previously impressed with its metal unibody so Samsung's drastic change, if it appears, could give the M9 a real run for its money. Expect the same aluminium body and front facing speakers with the rear sculpted to fit the hand.

Display deadlock

Face to face the HTC One M9 and Samsung Galaxy S6 screens are both expected to come in at 5.2-inches, but rumour has the Samsung coming with a Quad HD display (2560 x 1440 - 564ppi) while leaked wallpapers have suggested the HTC will stick with a tried and tested Full HD resolution (1920 x 1080 - 524ppi). That puts the SGS6 slightly ahead.

Samsung is also expected to release its S6 edge, which it has teased officially already. This should have a screen that curves over the edge to give a bezel-free look. But it appears there isn't enough screen on the edges to be functional like the Galaxy Note 4 Edge. Although that remains to be seen.

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Cyberport.de

Resolution aside though, it'll be down to personal preference. Samsung typically offers bright screens with punchy colours thanks to that Super AMOLED. HTC is favoured by some thanks to its sharp LCD. That said, on the last HTC One (M8) our review said: "The display also appears to be slightly warmer than the outgoing One model, which had brilliant whites, but overall we love the vibrancy of the colours and we've got little to complain about."

READ: HTC One M8 review

This round could end up coming down to personal preference, or perhaps how battery consuming those display variants are.

Power plays

One thing that is expected in this year's HTC and Samsung flagships is a variation in chipsets.

Samsung is expected to use its own Exynos octa-core processors while HTC should opt for a Qualcomm Snapdragon 810 CPU.

The Exynos chip that leaked in a benchmarking test was a 64-bit octa-core Exynos 7420 processor and ARM Mali T-760 GPU backed by 3GB of RAM. This is able to support up to Cat 10 LTE which would mean speeds of up to 450Mbps, something the UK doesn't even offer en masse yet.

The HTC One M9's Snapdragon 810 is a 64-bit octa-core with Adreno 430 graphics claimed to be 30 per cent more powerful than the Adreno 420 of the 805. It should also come with 3G of RAM.

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AnTuTu

The alleged HTC One M9 Geekbench 3.0 multi-core score was 3587. The Samsung Galaxy S6 was a hefty 5478. If these are accurate Samsung is the clear winner here – but how that translates to battery life will be more important than raw power for most.

Battery performance

With similar sized screens, which chew most juice, the difference in chip efficiency should play a part in battery life. That and battery size.

The Samsung Galaxy S6 is rumoured to come with a 2,550mAh battery. This sounds small so we'd hope that chip really is efficient. It’s also rumoured to be a wireless charging compatible battery that should mean wire-free power. This is, apparently, able to offer four hours use on just a 10-minute charge.

The HTC One M9 is expected to come with a hefty 3,500mAh battery. The M8 had a 2,600mAh battery and performed well so this could be a huge jump in life for the M9.

Real world use is the only way to really test battery performance so check back soon for our reviews detailing how these two lasted.

Getting snappy

The cameras on the HTC One M9 and the Samsung Galaxy S6 are going to be powerful and impressive whatever happens. But with HTC adding new tech almost to each device it launches what can we expect?

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Nowhereelse

For Samsung it's almost certain that the Galaxy S6 is going to arrive with Sony's 20.7-megapixel sensor running the show. Rumours also suggest a 5-megapixel front-facing selfie camera. It sounds like Samsung wants to make the photography experience easier than ever saying in an official statement: "It will be intelligent and do all the thinking for users, allowing them to take amazing pictures under any conditions, without having to worry about anything more than just pressing the shutter button."

HTC appears to be ditching the Duo Camera of the (M8) in favour of a 20.7-megapixel camera from which photos have leaked online. If this is the case The S6 and M9 could be using the same Sony sensor bringing any variation down to integrated options and speed. We'd also expect at least a 5-megapixel front-facing selfie camera.

Which skin suits Android Lollipop best?

Both the Samsung Galaxy S6 and the HTC One M9 will come with Android Lollipop as standard. On top of that should be their various UI layers with TouchWiz for Samsung and Sense 7 for HTC.

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Upleaks - YouTube

Samsung is expected to cut back heavily on its TouchWiz features to let Android shine through. Apparently the handset won't come with Samsung's usual myriad apps pre-installed but will have them available for those that actively want them. There is also expected to be a Theme Store that will allow for colour-coded personalisation of the device.

HTC's Sense 7 is expected to be more advanced with its Blinkfeed offering "meal time suggestions". HTC has been actively offloading apps from the core OS (e.g.: Blinkfeed, Camera, Zoe) into Google Play for more frequent updates, so Sense 7 is likely to bring in a run of changes separate from some of HTC's headline apps.

READ: HTC One M9 release date, rumours and everything you need to know 

Final expectations

On paper it's looking like the Samsung Galaxy S6 and HTC One M9 are very similar. Build quality should be high on both, with similar cameras. And even though the Samsung will have a higher resolution display we think, how sharp is sharp? Does that pixels per inch bump matter in the grand scheme of things?

What are more likely to make the biggest difference will be the power-to-performance ratio of speed and battery life. Those and how well the operating system skins work.

Expect both the HTC One M9 and Samsung Galaxy S6 to be revealed on 1 March from MWC 2015 in Barcelona. Pocket-lint will be there to be you everything live.

READ: Samsung Galaxy S6: What's the story so far?