I know some of you guys already have a 4K TV, but I thought I would post a review for those that don't. I bought the Sony XBR65X900C, for a recently finished sunroom. It was a great closeout bargain compared to comparably featured TVs, but this review is more on the 4K genre. Picture Quality...That's what 4k is all about...I have a 5 yr old 60" Samsung 1080P Plasma that I considered my reference TV. Once you start researching, eventually you will hear the term "upscaling". Meaning a 4k will take TV content formatted for something less than 4k and make it look better than the TV it was formatted for. I've found this to be true...a 4k TV will show 1080 content better than a 1080p TV...if you have 720 content, it will show it better than a 720 TV. CBS, NBC, ESPN, ABC, etc...1080HD football games look brighter and a little more detail than my plasma showing the same game, but not so much so that I would run out and buy a 4k TV. 4k content...you may have gone into a Bestbuy and seen the 4k demos running. The pictures are near live like. That said, don't expect to see the major networks broadcasting in 4k anything soon. They were dragged kicking and screaming into the 1080HD era...there's no ROI waiting for them if they invest tens of millions into new 4k cameras. There are a few sources for 4k content Netflix, Amazon, etc. but it's something you will be seeking for a number of years. Summary...At least within the next decade, 4K (or UHDTV) will probably never be a main stream format on par with HDTV...Why buy it? Largely because the TV manufacturers are practically forcing the new technology onto us by bringing the prices down very close to HDTVs. Secondly, most manufacturers have cut back on HDTV production so the selection is pretty limited compared to 4k TVs. Verdict...I'm happy with the new set...I can stream content directly from the TV, watch You Tube videos, and the picture quality is very good. That said, I wouldn't replace my HDTV with a UHDTV, but if you're adding a TV...it makes sense.