Having lived in O.C. all my life, I can tell you that life in many places is very similar to that. I went to high school with 15 year olds driving brand new BMW's. There are some parts in Orange County that aren't that nice (although still extremely expensive to live in..I'm talking $400k houses) but for the most part places like Laguna Beach, Huntington Beach, Newport Beach, Mission Viejo etc are quite similar to the show. You can find plenty of neighborhoods where the houses will range anywhere from $1 million to 5 million.
As for the show, I like it so far. There were a couple of cheesy parts like last weeks episode when they go off in the car talking about which punk bands they like. The stereotypes are definately there, but I guess that's what the show is supposed to be right?
Anyway, I think I'ma go bodyboarding at Newport for a while. Cya