From a more normal viewing distance, it's actually quite hard to tell the difference between watching 1080p and 4K footage. I sat 8ft away from the set because that's the distance between my AV unit and my sofa. It's a fairly normal viewing distance, although many people are likely to have their TV positioned further away from their sofa.
At 8ft there's still a perceptible difference, but I certainly didn't think it was as jaw-dropping as some manufacturers and industry types would have you believe. It's much, much, much smaller than the jump from SD to HD and arguably less than the jump between 720p and 1080p HD.
I was concerned that the 65X9005A's strong upscaling was reducing the apparent difference between the 4K and 1080p feeds, so I hooked up a 60-inch Samsung plasma next to it -- the closest screen size I had available.
I then downloaded a 1080p version from the Web of the same After Earth trailer that's on Sony's 4K player. Granted the Samsung plasma is smaller, so its pixels are more tightly packed together than they would be on a 65-inch Full HD plasma, but the X9005 has four times the pixels, so it should still be at an enormous advantage. Sony's engineers will also have encoded the 4K After Earth trailer at the best quality possible, whereas the 1080p trailer I was looking at was a Web download, so more than likely used much higher compression.
Back to back, from 8ft away, the difference between the 4K version on the Sony and 1080p on the Samsung really was shockingly small. I had to look really hard to tell them apart in terms of the detail in the picture. Even then I could only just about make out the difference between the two on sharp lines such as the graphics on the logos at the start of the trailer, and some details on the space suits worn by Will Smith and his mini-me.
Moving in close to around 4ft from the screens, the difference is easier to make out, but only on stuff in the foreground of the image -- and it's still not as big a jump in clarity as the huge hike in resolution would suggest.
I've seen recommendations that to appreciate 4K you should sit 1.5x the height of the screen away from the TV, but that seems absolutely, ridiculously impractical to me, unless you live in a shoebox. The KD-65X9005 screen is 80cm high which would mean that you'd have to sit just 120cm away from it -- who on earth is going to position their sofa just over a metre away from a 65-inch telly?
The upshot of all of this is that while the 65X9005 is a very, very good TV, the benefits of its 4K resolution at this screen size are pretty minute. You'd need a much, much bigger screen to tell the difference between 4K and 1080p sources from a normal viewing distance.
SD and HD picture quality
As we saw when 1080p screens first started to appear, successfully upscaling lower quality sources to higher resolutions can be a slippery eel. I was worried that HD and especially SD video would look pretty ropey on the X9005. Thankfully Sony's 4K X-Reality Engine actually does an impressive job when it comes to upscaling. Standard-definition sources are never going to look amazingly pretty when blown up to a 65-inch screen size, but they look better on the KD-65X9005 than I had imagined. In fact, all but the worst quality standard-definition channels on Freeview are very watchable on the X9005.
Blu-ray discs on this set are more impressive than on most normal Full HD TVs. HD broadcasts, which are naturally better, look softer on the X9005 than decent quality Blu-rays, but the difference is relatively modest. This is simply because good quality Blu-ray transfers look so incredibly good here.
In other areas of picture quality the Sony is also a very impressive TV, as you'd expect when you're shelling out almost five grand. Colours are fantastically rich, thanks in part to the set's high levels of brightness, which surpass what you get from even the best high-end plasmas. It's also very impressive at coaxing out lots of shadow detail from darker scenes, which make the picture very rich and nuanced. And despite a few hiccups here and there, it's one of the best LED screens I've seen when it comes to deep and inky black levels.
There are still a few niggles though. The screen's viewing angles aren’t all that wide. If you sit at an angle to the display -- say on an armchair slightly to the side of the TV -- the screen's colours start to look marginally 'off' with blacks taking on a bluey-grey hue.
Secondly, although Sony's backlight-dimming system really does work very well, it's not perfect. There are times when black and darker areas of the picture -- especially when they're sitting next to brighter parts of an image -- start to look slightly greyish. You also sometimes see hotspots in the pictures, where there's a difference in the apparent black levels in different areas of the screen. For example, during end credits on movies that have white text against a dark background, the black area around the text often looks lighter than the black in other parts of the screen.
Like all LED sets, with the motion processing turned off, the TV's motion handling is just so-so. You really need some motion processing kept on to fight this off. But to be fair to Sony, this model's motion processing engine is very good, so you can get rid of most of the blur without introducing a flat video look to proceedings.
3D picture quality
Interest in 3D TV seems to have waned alarmingly quickly, and one of the reasons is that people haven't been taken with the two 3D systems available on today's TVs -- active and passive. Lots of people don't like using active 3D glasses due to the flicker, while many don't like having to put up with the drop in resolution experienced when using passive 3D glasses on 1080p TVs.
The X9005 avoids both of these issues. It does use passive 3D technology, but because the TV panel's native resolution is much higher than 1080p, it's able to deliver Full HD 3D images to each eye, all without the flicker associated with active 3D glasses.
Make no mistake, 3D movies on Blu-ray's look great on this TV. Its 3D pictures are pin-sharp, suffer from virtually no crosstalk and are much brighter than those delivered by pretty much all of the active 3D TVs I've reviewed. The set handles 3D motion rather well too, and when you put all of these factors together you get a much more natural and watchable 3D experience. It really is a fantastic way to watch 3D films and one that might just change many people's negative perceptions about 3D in the home.
When you initially set eyes on the X9005, the first thing you notice is the huge speakers flanking the sides of the screen. They may not be that pretty to look at, but they do sound fantastic. In fact, the X9005 is easily the best sounding flat screen I've ever heard. There's no need to twin this set with a sound bar, as its own speakers sound better than many of the sound bars I've reviewed in the past.
The speakers are not as deep as you'd expect thanks to Sony's use of magnetic-fluid speaker technology, but they still manage to produce pleasingly warm bass, strong dialogue with plenty of presence and energetic high frequencies. They also don't suffer from the 'boxiness' that you usually get from flatscreen TV speakers. In short, they sound absolutely fantastic compared to the usual standards of audio from slim-line sets.
Given the Sony KD-65X9005's enormous price tag, you expect brilliant performance. Its excellent backlight dimming creates deep, rich black levels while also delivering bags of shadow detail, its passive Full HD 3D images are a joy to behold, and although its speakers are a tad ugly, they sound fantastic.
What you're really paying the premium for here however is its 4K support -- and sadly the benefits of 4K resolution at this screen size are extremely minor.