In general, you are better off betting it no matter what position you are in. Fold to any crazy check/raise or huge re-raise. The reason you are better off betting it is twofold: 1. You can take the pot down there. 2. You will get paid better when you hit your flush. Villain always suspects flush draw when you check/call, but if you are the aggressor then there is a higher probability that they will misread your hand and pay you off when you hit.