Stop in for a cup of coffee

Got a question about J heads. Can anyone tell me what the down side is to upsizing intake valve from 1.88 to 2.02 is (as compared to getting factory 2.02). I was reading on a thread about "bowl size" being too small if you do that, didn't really understand if that was critical. Comments?
No downside I know of. A buddy did that to his 318 heads and his teen screams!