The 55in KD-55X8505C is the honey trap for Sony’s 2015 4K UHD models. Priced considerably below the ultra-slim X90C and the hi-res audio-capable X93C/X94C behemoths, this is UHD for the brand-buying mainstream.

The design is conventionally thin, with a slim bezel and downward-firing speakers. It comes with a wireframe stand, rather than artsy pedestal or feet. The look may be cookie-cutter but build quality seems solid. There’s accommodating connectivity, too. You get four HDMIs, all of which are HDCP 2.2 compliant, so you can fill your ports with 4K native content as various sources become available. There are also three USBs, plus component AV, Scart, digital audio output and headphone jack. Integrated Wi-Fi is dual-band, allowing you to use the less-congested 5GHz band if your router supports it. Twin DVB-S satellite tuners and two Freeview HD tuners offer plenty of viewing scope.

This is an Android TV, which makes setup a little more convoluted than you might expect – you’ll need a Google account for full functionality.

Although it wasn’t live for this review, the set also offers YouView. Sony’s implementation runs atop the Android OS, and looks indistinguishable from the YouView platform seen on PVRs. While YouView here won't allow for timeshifting to USB drives, you can use the roll-back EPG for a full suite of catch-up TV services – BBC iPlayer, ITV Player, All4 and Demand 5.

Android's apps include Amazon Prime Instant Video, Netflix and BBC iPlayer – the latter being the only catch-up service supported natively. There's also Sony Select, which shortcuts you to channels you might have accessed via the old Sony Entertainment Network.

While all Android TVs function much the same, there’s a modicum of customisation evident here, headed by the Sony shelf, which sports a Watch TV button, random YouTube clips and other detritus. Below this, the Inputs shelf has to be manually edited to remove irrelevant stuff like Analogue Tuner. Scroll down further and you’ll also find an apps shelf, featuring the Google Play store, YouTube, various Google media services (Music, Games, TV) and Photo Sharing Plus, which is a JPEG casting function.

The Google Play TV apps store may be fairly limited, but does include Plex, Musixmatch TV, Vevo and Mubi – it’s essentially a mix of pay and free. But Android doesn’t have it all its own way. Sony’s Discovery bar remains an intuitive and engaging way to navigate TV and radio content.

Out of the box attraction

Picture performance can be spectacular. The screen is well configured out of the box, particularly in regard to its black level performance. Stored on in-set silicon are six 2160p resolution stills which betray astonishing levels of clarity. A desert cityscape holds detail down to its brickwork, only evident when viewed up close.

Picture presets include Standard, Vivid, Custom, Cinema Pro, Cinema Home, Sports, and Game. While you can dig through the menus to find theses, they are also accessible via the Action Menu. Of the two movie presets, Cinema Pro and Cinema Home, the latter offers better snap and dynamics. The Pro setting looks dull in comparison.

And if you have a fast 'net connection then you’re in luck. The X85C has an integrated HEVC decoder, and consequently the Netflix client is 4K-capable. Marco Polo (Netflix Original) is ravishing when it comes to texture and 2160p detail. Unfortunately the same can’t be said about Amazon Prime Instant Video – its implementation here taps out at HD.

Helpfully, the X85C also boasts excellent HD upscaling. The Will Smith android romp I Robot (Blu-ray), provides a tour de force of detail boosting. There's no pixel structure evident in the image beyond the film grain; up-rezzed resolution looks utterly convincing.

The set does black well. For I Robot, Smith wears a black leather jacket and trousers, topped off by a black beanie (it’s a strong look but he carries it well). Texture and tone on this high fashion ensemble are spot on – the latter is replete with fine detail and tonal gradations, while the jacket reveals authentic leather creases and folds. Shadow detail and contrast are great. Although edge-lit, screen uniformity is rather fine, too. There's little in the way of light pooling in the edges of the panel.

Motion handling, long a strength for Sony, remains above average. The Standard setting maintains image clarity, but can suffer overt MPEG motion artefacts. Clear is equally crisp, but exacts a brightness penalty. Opt for the True Cinema mode and you’ll be artefact free, although the result is a little shy on absolute detail. Arguably, the Custom setting is the best compromise for most material; try putting Smooth on '4' and Clear on '1'.

The colour fidelity on the Triluminos Wide Colour Gamut panel is high. The Live Colour setting allows you to alter the saturation of colours, amping or curtailing their vividness. The Low setting is best for skin tones, Medium adds a splash more saturation, while High is generally a little too much.

3D may not be fashionable, but the set is Active Shutter 3D compatible, with two pairs of spex supplied. The credit sequence to I Robot is set underwater. It's unclear what’s happening at first. Text depicting the three laws of robotics dissipates into oxygen bubbles. The sense of depth is pronounced, the airy spheres looking clean and free of crosstalk. It quickly becomes clear that we are looking at a submerged car – a passenger trapped inside. The window shatters and a robot rescuer reaches inside, toward us. The dimensionalisation is excellent.

The set’s audio is reasonable without being revelatory. Perhaps understandably the presentation is a little monophonic. You’ll be looking to argument this with an external sound system sooner rather than later.

Looking beyond Android

Sony has long been an admirer of Google's bigger screen endeavours – it was a backer of the ill-fated Google TV. Admittedly, Android TV is a better proposition, but it flies in the face of streamlined functionality. There’s little elegant about the platform. It’s also prone (at least for now) to slow firmware updates.

That said, picture quality on the X85C is superior to that of the much more expensive, ultra-thin X90C. Its images are punchier, boosted by a superior black level performance. So core Sony AV values remain strong, but with strong competition, particularly from Panasonic’s CX700 Firefox OS model, this affordable 4K Sony isn’t quite the slam dunk you might first expect.