I can't lump California wines under some massive generalization. Many better known brands are over priced, that's true for most things. I have had some lesser known ones that are truly exceptional. Steltzner made some incredible wines when he had his place. But if you buy Silver Oak, you could buy another brand at 2/3rds the price as good or better.
I like Far Niente a lot when I feel like affording them. Nickel and Nickel as well, same outfit. The great French wines almost all really need 25 years laying down to really be excellent, though that is changing I'm told.