This is hands-down the best monitor I have used for gaming ever! If you are old enough to remember CRTs the big box monitors, towards the end right when LCDs first were coming out CRTs were running at 120 Hz. I had forgotten how nice it was to have a really high refresh rate. You can see so much more clearly. You are able to get the head shots that you want because you can see. The ASUS ROG Swift works at 2560x1440 144 Hz and you can use G-sync, which makes everything even sharper. There is no tearing, no shuttering and no lag. This monitor is made for gaming on a PC with a really high-end in NVidia graphics card. It only works with the display port. I would not put the money down if you do not have a GTX780 or higher NVidia graphics card. You just will not get the full affect with a lesser graphics card. If you have the money, $800 out the door I cannot recommend this monitor enough for gaming.
I know you are probably thinking, for that price I can get a 4K monitor. Well, do not. The technology is not there yet, and the amount of pixels rendered on a 4K display are excessive, even with the newest NVidia graphics cards . In addition, most 4K displays have a maximum refresh rate of 30 Hz, which is unbearable. There are a few out there that can run at 60 Hz, none of which are televisions' only monitors.
Get this monitor if you are a hard core gamer.
Side note if oculus rift gets G-sync that will be the coolest thing in the universe.