And if you have the set, you have 7 outs on the turn and 10 outs on the river to make the fullhouse or quads. Almost as good as the flush draw! If you are pretty sure the guy is on a draw don't even think of folding 2pair or a set. If you are afraid of calling all-ins with a 3-2 edge, you are never going to go far in poker. It is different in a tournament where the best strategy may be to pick a better spot, but in ring play, if you have a 51% edge, you should push it (unless you are under bankrolled which is a problem you shouldn't have).

Also, your odds are better than 3-2 because of the money already in the pot.