Sony's flagship smartphone for the year is finally here and, for fans looking forward to its souped-up camera and high-definition 4K screen, the wait is worth it.

The Xperia XZ Premium is banking on its top-line specifications, an ultra-fast slow-mo camera mode and better display to stand out from the pack, but it is hampered by its bulk and design.

It's the world's first phone with a 4K high dynamic range (HDR) screen, which provides sharper resolution, and better colours and contrast.

Compared with a full-HD screen, the XZ Premium does a better job of smoothening out edges and sharpening images, although the difference is almost negligible at a normal viewing distance.

The HDR display also tweaks harsh contrasts and shadows, leading to overall smoother, richer and more dynamic displays.

Users who jump on board the 4K HDR ship too quickly may find content a bit lacking, since only the Amazon Prime Video app offers 4K viewing support for the XZ Premium. However, there are a number of YouTube videos which will render in 4K, but these are limited to wildlife demo videos and the occasional music video.

Furthermore, while the screen looks great, 4K HDR might be an overkill on the XZ Premium's 5.5-inch screen.

Such displays are great to look at on large television sets, but shrink it to the size of a regular smartphone and the extra pixels aren't noticeable unless you stare very, very closely at the phone.

Bordering the screen on both sides is a near bezel-less look, due to the XZ Premium's glass loop design that gives the phone its polished, premium vibe.

However, the phone retains the rectangular design of the Xperia line, with noticeably large top and bottom bezels that take up valuable screen real estate.

It's also a very shiny phone, which has the unfortunate effect of showing up finger smudges very visibly on both the screen and - especially - the back.

The same triple-stacked memory sensor in the XZs released this year - also usually found in compact cameras - returns on the XZ Premium.

This lets the phone take and process images at very high speeds, which is essential for the ultra slow-mo and predictive capture that Sony is pushing as standout features of the XZ Premium.

The slow-mo feature, which takes up to 960 frames per second can be a bit of a gimmick, since it applies only to certain fringe cases. There is a long list of requirements before you get usable shots: being outdoors, careful timing and strict coordination.

The predictive capture mode, which senses motion when you are preparing to shoot and which takes up to four photos of quick action even before the shutter is pressed, is by far the more useful feature.

This lets you have greater leeway when capturing action shots, as there is a buffer time to compensate for any lag when shooting.

Photo quality on the XZ Premium is exactly as expected on a flagship - sharp and clear, with a balanced intensity and detailed contrast. There is a slight shutter lag, though, and a fair bit of over-processing for low-light images that make photos look a bit unnatural when zoomed in.

The new Snapdragon 835 processor makes the phone feel blazingly fast, and it's easily one of the fastest flagships currently in booting up, firing up applications and multitasking.

Having stereo speakers is a big plus for the XZ Premium as well, as it pairs very nicely with the screen to let you watch videos with good audio and visual quality.

•Verdict: The Xperia XZ Premium is what Sony fans have been waiting for this year. With a great screen, useful camera features and powerful hardware that drives the phone, the XZ Premium is a good pick for those who value multimedia consumption and don't mind a larger, bulkier phone.