Does it actually take 75hz? From what I remember you can always pick 75hz in windows and practically all LCDs will accept it, but that doesn't mean that its displayed.
Yes it does. And no, you can't always pick 75 Hz.
I had to use a utility to set the 75Hz as standard so it would also be used in games and not just on the desktop.
Quick update.
Decided to bring out the 23.6" Full HD screen again and I think I do prefer Full HD now. The screen is a cheap AOC with lots of ghosting, light spots and poor colours so I have my eye on a relatively affordable Asus 24" with 1ms speed, the VX238H.
If I play at medium rather than ultra, I agree, the fps is just fine with the GTX660 and doesn't look that much different to be honest. Currently I only play Black Ops but looking forward to Ghost and BF4. I tried playing FPS games on the console, but growing up with Doom on the PC I simply can't get used to these painful little sticks on the controllers. Gameplay is sooooo slow and frustrating and although on the PC the pace is brutal I do prefer this.
So yea maybe a 1600 x 900 screen would be better, but they have basically disappeared and they are all slow 5ms and you can hardly find good reviews on them.
Thanks for the good discussion and pointers. It was very helpful.