As long as you have a nandroid backup made then you have nothing to lose. You'd be amazed at how much better your phone will perform if you flash a custom ROM on it.
i am a total noob (first android) and mt and the guys here have made it incredibly easy to play around with this phone....mine is gingvervolted/blitzed/supercharged and it is like a totally new phone. my wife looks at me and says, "are you messing around with that damn thing again?" lol
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?