I think it is good to know the difference and how much it can be. You do have to play on the table in front of you (or not play at all) but it's wise to know what you're dealing with and how it will affect shots.
I think it just the much much different when you play in tournaments, bc it’s all new cloth, but after like a week new cloth, still not a big deal to play, of course better then old cloth but not really to much