feeling it was never my problem but when i had a 45ms lag TV i could not effectively play games online because i would have to lead targets by a very very unusually high amount esp when flying planes in BF1942.
i'll lay out the BF42 scenario i noticed big time because its the best example in to me, i used to play this game competitively as a pilot back in its hay day and i was one of the best pilots in the game.
to be a good plane pilot in it there are two things that input lag effects greatly and 3 frames of lag is just too much to work with.
#1 is timing of dropping bombs on a tank, if you get good at timing this and you can drop the bomb on the rear of the enemy tank it will blow up in one hit, if it hits anywhere else it will just take damage. i used to be an expert at doing this and with my 32XBR6 (3 frames of lag) i could never get it to happen ever because my visual timing was so thrown off by the TV.
#2 this is the big one, one that could not be corrected by adjusting for it over time mentally. when dog fighting the fastest and best way to take down an enemy plane when your on their tail is to predict when they are about to bank left or right and get you cross hairs in front of them by the right amount so you guns hit their engine and they go down super quick, any other way like shooting the tail section just takes too long to down them and gives them a chance to get away. on my 32XBR6 i could never lead them far enough to hit the engine plus i was banking to late many times because 3 frames had passed in real time before i seen them start to bank. this is very important to being a successful pilot in this game.
so when i was going through this trouble i was getting like 2-4 kills in a round on a server i thought to myself hey maybe its the input lag that is causing me to suck so bad. so i put my 22" PC monitor in front of my TV on my desk, jumped into the very same server i was in and sucked in moments before and guess what i finished that round in 2nd place with nearly 20 kills!
with my Panasonic 37S1 i also have no problems racking up kills and actually play a bit better because of the larger display.