super late to this conversation, but i have a Sony 55" 4k (its not full 4:4:4 color until they release an update for it and you WILL need a HDMI 2.0 video card to do it)

HOWEVER, it is amazing. I run my clients in windowed mode and only usually play on about 1/3 of the screen real estate.

For me it was totally worth the price (about 1600) compared to buying multiple 4k screens.

It has one of the best response rates around and was rated excellent on displaylag.com for using as a gaming monitor

http://www.amazon.com/Sony-XBR55X850...ywords=sony+4k