I have been using 1440 res for gaming for the past year and its a nice step up from 1080p & i loved it , But I purchased the new 4k Asus friday and WOW !! right out the box the picture was gorgeous , first thing i did was go and download some 4k UHD backgrounds and the detail has to be seen to believe , I have been running BF4 on ultra settings with AA off as you don't need it at this res and I am getting a constant 50 -55 fps and jumps down to 35 - 40 when massive explosions go off in your face so a really playable experience, I was using ips before and with this new monitor my kill ratio has doubled

First of all you will never a see a better looking game , It looks super smooth and it looks gorgeous , I can honestly say I wont ever be using my 1440 res for gaming anymore , The only problem at this moment in time is cost and the fact they have some issues with these monitors , I will be sending mine back monday not because its a bad monitor in anyway but I have a lumance issue with mine on white backgrounds so going to get it replaced , Id say this time next year when single cards will run 4k perfect 4k will really become mainstream, Sony have put a lot of money in to this format & it is beautiful to look at ,
I'd say if you got a good graphics card then go for it.