I've done ecstasy... let's see, about 5 times give or take, and my only bad comedown was my first time. Mainly because I took about 5 1/2 pills and I was tripping balls. It wasn't that bad though, I rested the following Sunday and went to class on Monday with no problems.
I've never done mollies/pure MDMA though, so I can't judge it. It's probably not as intense as ecstasy, mainly because you don't get the energy, just the euphoria. The pills I took a few months ago were really high in MDMA and I was incredibly happy, but had no energy. I don't really like high MDMA and no speed/meth, as horrible as that may sound.
And I love how you said you won't try it because you'll always want to recapture that feeling. You find a flaw in something being TOO good. Anyways, I roll maybe 3-6 times a year, only at raves, and I've suffered no negative effects from it.
It's the stupid kids who try to take 9 pills and drop acid at the same time who give ecstasy a bad rep. Last rave my friends and I talked to to a guy who said that's what he'd take the next day, and the following night I saw him sucking on a pacifier, drooling, being lead around by some fat chick.
But yeah, E is a life changing experience, and I recommend it to anyone who is healthy. It's like no other drug out there.