It was uncomfortable as hell when playing games that used analog mode (which is practically the entire library) but for the few games that used digital mode (mainly WCW and WWF games like No Mercy) it was bliss.
My launch N64's original controller still works just fine. People abusing the hell out of the controllers wore them out (apparently certain Mario Party minigames caused a lot of this) but people who actually treated them right had little to worry about.