I was looking at 4k tv's myself these last couple of weeks as I've decided to treat myself to an early Xmas present but after reading up on the 4k's I decided not to bother basically based on what Ross has already mentioned. So I'm going for the one below as all the reviews I've read are mostly positive with very little negatives apart from the weird magic remote thing and it was one of the What Hi Fi Sound an Vision TV's of the year too. I'm not terribly fussed about 3d or the smart features tbh as I am on Virgin Media, but it still seems a decent set.
http://www.richersounds.com/product/...sams-ue48h6400