It's a strange thing to say that a major highlight on one of the first 55-inch Ultra HD TVs is, in fact, sound quality. But that's exactly what the KD-55X9005A excels at, along with searing amounts of 4K detail and a fine upscaled Blu-ray experience.

We liked

Aside from detail, the KD-55X9005A does brilliantly with colour - and even better with sound.

In fact, we'd rate it as the best-sounding TV around. The design is high-end, the user interface slick and the 4K detail stunning. More importantly, at least at this early stage of 4K evolution, is upscaling, and some good news; Blu-rays have never looked better - and that goes for 3D as well as 2D discs.

We disliked

If most Full HD TVs are best fed an HD-only diet, that goes quadruple for the KD-55X9005A, which doesn't make as much of the 4K detail as its bigger 65-inch sibling.

Standard definition sources look rather ropey, and we also noticed some issues with contrast and the 4K-cancelling amounts of motion blur.

We're also not convinced that built-in speakers - and the consequent super-wide design - will appeal to the kind of home cinema aficionados that are bound to be most interested in the KD-55X9005A. At 34.5kg it's a whopper, but is it really big enough to show-off 4K?

Final verdict

With only slightly less wow factor than its big sibling, the far pricier KD-65X9005A, the KD-55X9005A is currently the best value Ultra HD telly around.

But it's not just the pin-sharp performance with (as yet non-existent) 4K sources that blew us away. As if to throw the AV world a few crumbs as we await 4K Blu-ray, Sony's provision of some awesome speakers flanking the 4K panel are a timely reminder of just how much cinematic impact is from sound.

Colour, too, is stunning, and the upscaling of Blu-ray is proficient.

The downsides are a touch of motion blur and the somewhat ropey-look to upscaled standard definition sources, where the maths involved proves too much.

One of the best performers with Blu-ray, let alone 4K, the KD-55X9005A is a standout winner with 3D, too. The passive 3D system's loss of resolution here looks less like a compromise, and it's always smooth and bright. Until we wait for native 4K Blu-ray discs to drip onto the market, the KD-55X9005A has plenty to keep anyone satisfied.

Also consider

Also offering 55-inch-or-thereabouts Ultra HDTVs is LG, Samsung and Toshiba.

LG's effort is the 55LA9700 and Samsung's the UE55F9000, which are both identical in price to this Sony.

If you want to save a few quid, head for Toshiba's slightly larger 58-inch 58L9363DB (£2,999).

Both Samsung and Toshiba use the Active Shutter 3D system on their Ultra HDTVs. Most are available in 65-inch versions, too, but the prices almost double.