I saw a guy saying that it was literally impossible to play osu with 17ms and 60fps, I've been playing like that for a while, is it really that bad? note: now I have disabled vsync and it is at 3ms now
It's pretty bad, especially if your monitor is over 60 hz. It's not at the level of being unplayable but you should definitely feel some improvement going to 3 ms, especially with a >60 hz monitor.