Caffeine is my only stimulant experience, but i swear it is like night and day sometimes.
Caffeine, if I'm "up" to begin with just sends me through the roof, I feel awesome (not relaxed or euphoric) but just confident and good.
If I'm tired, and a i drink 200mg of caffeine I basically smash my head on the counter from passing out from tiredness.
....Yeah. Caffeine doesn't really compare though so what the hell am I posting for.