I turn almost all that shit off, also dont play many cover based shooters.
you are thinking response time, not input lag.
also, that response time is fucking bullshit otherwise the ghosting would not be perceivable.
gaming, i like to sit back, recline, i hate sitting up straight to play a game, with a crt this was easily doable. I have a tn panel as my monitor, and leaning back means any dark area in a game is now completely black, I have access to one of the best ips monitors you can get before you go into pro monitors for accuracy, and looking at it from a reclined position its still fucking off enough to make everything look black.
Now, personally, the most important thing in a monitor isn't color accuracy, its contrast. this is the single biggest thing you will notice in how the monitor displays a color, its honestly amazing how off a monitor can be color wise and you dont notice it, but contrast is one thing you will always notice more pronounced.
after that comes fps, having seen a 60 and 144 right next to each other, jesus, you would never know how bad just doing normal tasks on a 60 hrz is.
i put free sync/gsync above fps when the range is down to 20 and up to max the display can show, this is because it effects when the monitor shows a new frame, holy shit, i never knew 20~fps (we down clocked the gpu to get this) would feel so good, and this is coming from playing ar around 120fps a few minutes before.
then color accuracy, personally, well calibrated tn will match most ips that a consumer would pick up, so for me, its not to much of an issue, at least not a 'holy shit, this would be worth dropping 500~$ on' as i was considering a few months back. either my monitor, a syncmaster t240hd is just that good of a tn display, or ips are way to fucking overhyped, im not sure which anymore.
and then resolution, as the most noticeable thing, so long as you have about 100ppi you are good.