Mobile World Congress was about two things: HTC and Samsung. Both launched new flagship devices, with similar launch dates, looking to dominate 2015 with new devices.

We've now lived with both devices, so to help you decide which it worth your money we're pitching them head to head. Should you choose the HTC One M9 or is the Samsung Galaxy S6 that's going to be your handset for the next year or more?

Be sure to read our Samsung Galaxy S6 review or our HTC One M9 review if you want much more detail on both of these handsets.

HTC had a design hit with the HTC One M8 and has kept much of the looks for the HTC One M9. But it isn't the same, it's been refined to the nth degree. There's precision and a quality of finish that's rare, making this a luxury metal handset. 

Samsung knew it had to change, and it really did. A metal frame houses Gorilla Glass 4 front and rear panels. It's a big change for Samsung in terms of design, showing it's responding to criticism at this flagship level. 

Of the two, the change from Samsung is the more dramatic, the SGS6 is the device that brings a new look for the brand, where HTC could be accused of resting on its laurels. The Samsung feels new, the HTC feel familiar.

The Samsung Galaxy S6 measures 143.4 x 70.5 x 6.8mm and weighs 138g. The HTC One M9 is larger and heavier, coming in at 144.6 x 69.7 x 9.61mm and weighing 157g. We'd hand this one to Samsung: it feels more original this time around, but there's no denying the quality and attention to details from HTC.

Both HTC and Samsung offer octo-core 64-bit chipsets in the new handsets. HTC has used Qualcomm Snapdragon 810, with 3GB of RAM. 

Samsung has made the decision to make a departure from Qualcomm, instead using its own Exynos hardware for the processor. Exynos has been used in some markets, and some devices, previously with good results. Again, there's 3GB of RAM. 

Of the two devices, the Samsung feels faster. HTC has some elements of it's user interface that are slicker, but when it comes to things like opening big games or just starting up the phone, Samsung takes the lead.

In a change from previous years, the Samsung Galaxy S6 is now a sealed unit, meaning you can no longer swap the battery out. The Samsung Galaxy S6 has a 2550mAh battery. The HTC One M9, however, has a larger 2840mAh battery. There's not a lot in it, but HTC has the higher capacity.

The Samsung Galaxy S6 offers wireless charging built-in, which HTC doesn't, although both offer fast charging, with Samsung claiming to offer the fastest charging battery around. 

Neither device is a step forward over previous years, but it's HTC that the slightly better performance in the battery department. The Samsung will falter first on heavy days, but in lighter use, both will make it through the day.

The Samsung Galaxy S6 features a 5.1-inch Quad HD display, meaning it packs in more pixels for an incredibly sharp 577ppi. As on previous devices it's a Super AMOLED panel.

The HTC One M9 sticks to a 5-inch 1920 x 1080 pixels, 440ppi. That's quite a difference, although visually, Samsung's increase in resolution doesn't result in extra detail that makes a difference.

The SGS6 has pop and punch that the HTC lacks, with more vibrancy to colours. Both have great viewing angles, but the HTC is better capable of producing brighter, cleaner whites thanks to its LCD panel.

One minor thing to remember is that HTC has on-screen controls. That means you get a little more space on the Samsung, because it has capacitive controls below the display.

Where HTC has made some innovative camera options in the past, the M9 is more conventional, with a 20-megapixel rear camera and a 4-megapixel UltraPixel front camera.

That's a good pairing, as the UltraPixel sensor is well suited to low light conditions, making it ideal for taking selfies, although they often have a pink tinge to them. The rear camera on the HTC suffers badly from low light noise and is too aggressive in processing, often smearing away details. It also has a yellow cast to photos.

Samsung on the other hand is coming from a position of strength in cameras, with previous devices like the Note 4 being very good. A rear 16-megapixel and front 5-megapixel camera makes for a good pairing, with a newly overhauled camera app that's designed to be really simple.

The results are impressive. The Samsung Galaxy S6 delivers consistent, good quality results from its camera, also offering optical image stabilisation that are a step above the HTC One M9.

Samsung's sencond attempt at fingerprint security has been pulled off really well. The HTC One M9 offers no such security measure so you'll have to tap in the password to unlock it, where the SGS6 just needs a touch.

It's well implemented, making it a natural action, rather than the unfortunate swipe it was before. It might seem like a small thing, but if you access your phone constantly throughout the day, it really does make a difference.

These are both handsets that pack in plenty. Both offer the latest Android 5.0 Lollipop and come with additions and revisions through TouchWiz and Sense 7. Samsung has added the convenience of Samsung Pay, meaning mobile payments on the move, HTC offers plenty of refinement and maturity. Both have reduced the bloat in these latest iterations.

There's plenty of power to run the latest apps and games, but the SGS6 display is more capable. HTC might edge it out on battery, however, thanks to the more restrained use of pixels.

In the design department both handsets are now premium, with HTC's luxury metal, and Samsung's move away from plastic, to metal and glass. Many will see Samsung as making the biggest move here, a distinct change of direction, rather than the evolutionary refinement from HTC. 

These devices are closely matched. HTC offers slightly better endurance, we Samsung appeals with the camera and display and a new premium design.

You can find the best deals on the Samsung Galaxy S6 here, of if you prefer the HTC One M9, you'll find the best deals right here.