well, my epxerience with pure MDMA capsules are basically: they're a lot less "up-and-down" as normal caps. I'll come up, plateau, go down for a bit (not too far down), come back up to where I was, plateau, etc etc etc. Until I start to REALLY come down. It's kinda fun. Not much of a hangover either. Just a "what the fuck happened" feeling, as I tend to take lots of pure MDMA if I get the chance.
MDMA caps, though, sometimes, I like the speedy feeling, me being a fast person (i like speed, as in the rate of speed of things). so I like my drugs to make me feel like that.
But when it comes down to it, I guess it really depepnds on what you're gunna do that day. You just wanna chill with friends? Pure. Wanna go dancing? Pill (with whatever's in it).