As far as fast food burgers go, Five Guys burgers aren't that thin. Sure it's not thick like a specialized local burger joint, but compared to everywhere else, it's certainly a big step up. I guess that's to be expected though considering it's also more expensive. I don't think of Five Guys as the same kind of fast food as McDonald's, Wendy's, BK, etc. Never been to the West Coast, so I've never had In-n-out.