Yeah, I bought it for myself for Christmas.
OK, not really, but I've seen it at Sony Store in Manhattan on Madison Ave.
It does have its own room but that room is in the furthest corner of the basement level.
Picture quality in 4K is amazing, there is no other way to put it (I have seen only 2D material). The source for 4K content is some kind of hard drive based server. And here is the thing: upon close examination I strongly suspect the video is uncompressed - it looked like EACH PIXEL was different on scenes with high detail level, no compression artifacts at all no matter how close I looked. That is you will never get this kind of quality from any commercially available source (let's ignore for the sake of conversation that AFAIK
presently there are NO 4K sources at all commercially available - when/if they become available I doubt they will provide uncompressed video).
God that Taylor Swift music video was annoying!!! It was like... so whatever...
So after enjoying that music video and other 4K material I asked sales person to put a Blu-Ray disc on. What a disappointment!!! The disc was "Tron: Legacy" (2010). I personally didn't care about this movie at all, haven't even seen it before. I don't know if disc mastering was not very good, but picture quality was just awful comparing to 4K material (OK, maybe somewhere between awful and mediocre but closer to awful). The part of the movie I saw was mostly dark, so lack of shadow details may have contributed to it. The best way to describe it is it looked like badly mastered DVD comparing to well mastered Blu-Ray disc. 2 main problems I noticed immediately were general lack of details (like when compression ration is too high) and pixel crawl (or is it called mosquito noise? the last time I've seen it was I think on VHS tapes). On this disc there was also a trailer from the latest Pirate of Caribbean movie (the one with vicious mermaids) and even though it looked a bit better is still experienced the same problems.
Later I had a chance to see the same Blu-Ray disc on "regular" 60" Sony TV (I think it was EX line) and it looked perfectly fine. Not the best picture I've ever seen but nothing to complain about.
So for me a conclusion is that for me 2K Blu-Ray is not sufficient for this TV when built-in upscaler is used. And even for 4K source a lot will depend on compression level (again, I suspect 4K material that I saw there was uncompressed).