It just depends. I've noticed A LOT of molly lately that isn't MDMA.... it's mephedrone..... bk-mdma, mdpv..... or something else. Pills can be the same way...... there can be some that are real and great..... but there can be other people out there making the same color/design pill with nothing but junk in it. Some people enjoy the fake crap..... but to me, nothing is the same as real MDMA.
So......... my conclusion is....... buy both to find out which is better =)
Unless you KNOW the distinct MDMA smell/ taste..... then take a good whiff and taste of the molly, and decide from there (that's what I'd do)