Mate has mateine, by the way, not caffeine (mateine is a stereoisomer of caffeine). I don't know it has different properties and that's the reason or if it's the plethora of other constituents, but in my experience mate gives me a mild, persistent buzz all over my body as where caffeine goes straight to my head.
It's the other alkaloids that contribute to the effects that are different than coffee.
Also, it only took me about 3 days to feel normal, and a coupla weeks to not really want it very much, after 5 years of averaging between 3 and 4 2L Diet Mountain Dew a day. It helped that my wife was very vocal about how much less stressed I seemed; after I was off of it, she suggested I just stay off even when I can afford it, so I'm doing that for now.