Durlston
"You plonker, Rodney!"
definitely does the latter....no sure about the first bit , prolonged use also leads to brittle bones , rotten teeth , renal and liver failure , cardiac problems but the short term effects for a lot of users is manic violent psychosis and generally turning into a top shelf fukwhitt ......to say it is mostly used by gays is just rubbish.
I've never done crystal meth but from what I've read and from friends experience it sounds like base which is a much stronger form of speed. Went 72 hours without sleep on it.