We finally got some 4k tv's in store in Australia that i was able to have a look at in real life (finally) and all i could do was kinda laugh at how stupid it is on a tv less that 65inches and even then, I stood there and kept walking backwards until the detail was lost and it was pretty dam quick, and my eyes are dam good. At 3 meters back all benefits are lost on a 65inch tv making it a complete waste of cash that you just wont see in a normal size living room. And here's the kicker, they all showed pixelation issues when trying to display high speed content so most of the demo's are slowed right down on purpose. Absolute fail tech, i don't recommend these first models to anyone at all (ask if it has hdmi2) and google the model specs if your really that keen on one of them. The sony's where the worst with horizontal lines all through the picture (seen this issue on 5 different tv's in 3 different stores) and the the panasonic 65inch one was the pick of the litter if i were to choose the best one.
The best possible situation for 4k is pc monitors when your sitting less than 50cm away, but nooooo instead of pushing tech where it would show of its true benefit they release tv's that are to small to show it off just so they can say 'hey looks its new, it must be better' so give us your cash cause tvs have stopped moving of the shelves big time.