Asus hasn't had a great deal of success breaking into the UK market with its ZenFone smartphone range, but that could be set to Change in 2015 if the newly announced ZenFone 2 is any indication; we got the chance to put the 5.5in, 4G flagship handset through its paces today at CES 2015, and walked away impressed.

Whereas the original ZenFone line-up was aimed sqaurely at the mid-range, the ZenFone 2 is clearly designed to sit at the top of the range. The metal finish on the back of the handset immediately makes it stand out against the matte plastic finish on the other models, while the curved sides sit comfortably in the hand. It's only 10.9mm at its thickest point, but at the sides this slims down to just 3.9mm. The power button is on the top of the phone, but Asus has taken some inspiration from the LG G3 and moved the volume keys to the rear. If you aren't a fan of the bright red model seen in our images, Asus has several other colours available, including black, white and silver, plus a range of more outlandish metallic finishes and designs.

Despite using capacitive buttons rather than onscreen navigation keys, the front of the phone is almost all screen, with thin bezels around all four sides that means it doesn't feel like you're holding a 5.5in handset. That screen is a stunner too; it's an IPS panel with a pixel density of 403 pixels-per-inch (PPI), paired with a 400cd/m2 backlight for incredibly bright, vibrant images. The 1,920x1,080 resolution means text and images are very sharp too. We'll have to wait until we get a full review unit to run our full range of display tests, but on first look it seems like the ZenFone 2 will be able to hold its own against the current crop of Full HD handsets. Asus has also used Corning's Gorilla Glass 3 on the front of the handset to protect it from scrapes and scratches.

On the back, the rear camera has received a minor upgrade over the current crop of ZenFones. The 13-megapixel sensor has an f/2.0 aperture lens to let in the maximum amount of light per photo, while a twin LED Real Tone flash should help produce more realistic images in low-light. Asus is so convinced of the ZenFone's low-light abilities that it was using the handset to take photos in near darkness; we can't vouch for the image quality just yet, but it certainly fared better than a Samsung handset set to a similar camera mode. It also includes HDR and depth of field shooting modes, with the latter creating convincing depth blur during our time with the phone.

Inside, the ZenFone 2 uses intel's latest 64-bit, quad-core Atom Z3580 processor running at 2.3GHz, paired with a massive 4GB of RAM. It's the first Android smartphone to do so, and although we have yet to run any benchmarks, Android felt incredibly snappy and responsive during our time with the phone, especially when switching between apps or playing games. You also get either 16, 32 or 64GB of onboard storage, plus a microSD card slot for adding extra capacity at a later date.

The Atom chip should be fairly frugal when it comes to power consumption, and with a 3,000mAh battery inside the ZenFone 2 should easily last a full day on a single charge. When it is time to refuel, it has fast-charge support to bring down recharge times.

Asus has used the latest Android 5.0 Lollipop build as a base for the ZenFone 2, then added its own ZenUI interface on top, upgraded slightly to match Google's Material Design scheme. Smart notifications on the lock screen and a more comprehensive list of shortcuts on the pull-down notification tray are both welcome additions, although we aren't sure whether the custom app drawer is an improvement; it feels suited to older versions of Android, although you can at least customise it more than the vanilla ROM.

With a more premium feel, much improved screen, latest version of Android, very capable camera and an incredibly snappy performance, the ZenFone 2 looks like it could be a serious contender for mid-range phone of the year. It's set to launch in the US from March at $299 for the model seen here, which works out at roughly £199 before tax and VAT. That makes it a compelling alternative to mid-range marvels like the 2014 Moto G.

It remains to be seen whether Asus will have an easier time getting the ZenFone 2 into the UK than it did with the original line-up, but based on what we've seen so far we're hoping we won't have long to wait until we're able to get our hands on a final retail version.