yes technically i agree with you and you are right. The op wanted to know if there was going to be a compromise and there will be. Not slightly, but a whole lot.
Few frames might not be much on paper, but from my experience its quite a lot.
Have you played Trackmania? its quite a precise game, the driving techniques with power sliding requires precision timing and if you had to compensate as well for input lag, it will make things a whole lot more difficult.
You will learn of course in time to compensate, but why bother in the first place if you can do something about it?
I bought Samsung 32" lcd to be my initial display, thinking 32" would be big enough from where I’m sitting, didn’t know about input lag at the time. Playing Trackmania on it was a nightmare and so was Halflife 2 and would be the same for any fps game and probably wow too. Its like you're trying to move around in water and just more annoying than anything else.
I tried Trackmania on the lounge room tv which is a plasma to see the difference. The lcd ended up outside and bought a plasma 42", smallest sized at the time i could get and couldn’t be happier. If i knew i would have got that in the first place, which is why im typing all this to save op hassles. i dont mind
even if he doesn’t go this route or already has an lcd tv.
All in all, plasma technology = zero input lag.