Now I'm interested in the distinction.
hmm well i think people who prefer uppers either like it for the extra energy it gives them for work/projects or they use it to keep themselves socially "up" and confident. especially when paired with drinking, it cancels out the drowsiness of alcohol and makes one able to party all night and talk incessantly. try to stay away from methheads so not a lot if experience with them, but cokeheads are annoying as fuck.
downer people are escapists. not that all drugs aren't an escape in a way, but they're the most numbing and comforting. it can help socially by making someone less anxious or reducing inhibitions but i don't see it as much as a party thing. for people who like to slow their mind down. can easily take over someone's life.
hallucinogen users are bored with the confines of reality and are hoping to expand their mind and find some secret to help themselves understand the world better. vast majority of people I know who've used these drugs do them very occasionally, the people who do it too often are wacked out nutjobs completely out of touch with the world.
typologically speaking hmmm..
(i'm definitely pulling this out of my ass right now, very loose associations)
uppers: 3, 5, 7, 8, so
downers: 2, 4, 6, 9, sp
hallucinogens: 4, 5, 7, 9, sx
let me add that those categories are not mutually exclusive, lots of people fall into multiple categories or just like any drug available. and i can think of many exceptions.