I've been an FPS player since Wolfenstein 3D and played a bunch of Counter Strike Beta until about four years ago when I moved solely to the PS3.
My skills are above average but with the release of Black Ops 2, I was getting extremely frustrated with a crappy KD. During the holiday season, I brought my PS3 into the office to kill time and mated it with my Dell 24" monitor and started tearing games up.
I have about 13,000 total kills right now and in the last two weeks I've gone from a .88 KD to 1.11 (as of last night) with some games of Headquarters nabbing me 80+ kills.
Bigger does not necessarily mean better but it also has to do with how close you sit to your TV. My brother-in-law plays on a 52" Samsung but he sits three feet away vs. my and my 55" LG where I sit about nine feet away. I tried sitting closer but I just couldn't do it.
Right now, I sit about two feet away from the 24" monitor at home and am having a lot more fun with BO2.