Input lag is more important than many people realize. A few years back, I never even thought about it. I was playing my games on a TV that had horrible lag (it was an old 22" Samsung LCD) and never even noticed for years until I bought a bigger TV (32" Insignia) that had considerably less lag. The difference was immediately noticeable, athough I didn't realize (at the time) that it was because of input lag. Suddenly I was doing better at racing games and I was hitting the flippers too soon in Pinball Arcade.
I never could find any data about input lag on the old 22" TV, but it must have been ridiculous because the data on the newer TV said it was 28ms, but the difference was very profound and instantly apparent. Now I have a 40" Samsung with 20ms lag and I don't really notice the 8ms lag difference with the Insignia, just picture quality. So like I said, that old 22" must have had ridiculous lag.
Anyway, that was when I discovered the importance, as well as the existence of input lag. Trust me, you will get used to whatever you're playing on and won't even notice lag until you experience something better.