Input Delay:
A delay of the mouse was after power available (but roughing it)
By activating the settings> Picture> Picture Mode> Game it's almost gone.
As a professional gambler, I would still prefer to resort to a monitor.
Old Graphics Card:
4K with old (> = HD5X) ATI graphics cards is also possible.
I use an ATI 6870 with a resolution of 3840 x 2160 @ 30Hz which is definitely more pleasant than the interpolated FullHD.
So we need the tools ATI Pixelclock Patcher and Custom Resolution Tool (Google simply by "ATI Pixelclock Patcher" and "CRU ATI" Search)
With Nvidia should be possible like.
Picture:
Absolutely perfect. Black is black and white really white, contrast also top.
SmartTV:
I do not use this feature. But the TV played from almost all kinds of MKV files. But my 2 tested 4k videos did not go (only on the PC).
Hope this helps with your purchase decision somewhat.
PS:
I bought the TV yesterday in flash range for 499 and this will not send back.
Soon even get a GTX970 with HDMI 2.0. This should then also be in there 60Hz.
