Yeah, its easy to see. Especially after you have gotten used to playing at 60 FPS, and suddenly things that were smooth are jerking slightly. Sometimes even stuttering. There are some games that do play well at 30 FPS. And there are games that really need more than 60 to play real well. But nearly all games do fine at exactly 60 FPS. Mainly because that is what the developers aimed for, and so that is where it looks best.