I agree on the diet drug part... I've lost a lot of weight with DMAA. I think the body buzz is very enjoyable, and I get a mood lift from it, similar to a post-workout mood lift. I find DMAA has less anxiety than caffeine, and almost no negative peripheral effects.
Really is too distracting for work, though. Each dose seems to only last 2 hours for me. No noticeable crash/comedown from up to 300mg over 8 hours.
Propylhexedrine totally spanks DMAA in terms of a high.