DL was great! The Grand Californian is a beautiful hotel and we felt that it was well worth the points. ( 32 pts. a night during the week after Easter) You are right in CA which made it very easy to go back and forth from the park to the hotel. The MK was a five minute walk.
CA is still working out some growing pains. The Paradise Pier section is a seaside type of amusement park. My husband loved California Screaming. The Golden State section is themed to different regions of California. Some of the attractions are the same as in WDW like the Muppets and It's Tough to be a Bug.
The best attraction IMO was Soaring Over California. You really feel like you are flying. I would really like to see them put this attraction in WDW -maybe a Soaring Over America in Epcot. They are also building a Tower of Terror. If you are a fan of the Electrical Parade, you can see it there.
The Magic Kingdom is more detailed than in Flordia. Fantasy Land is more elaborate. You can see and feel Walt's touches in this park.
Since there are only 2 parks and a Downtown Disney area, you only need 3 or 4 nights to do it all. CA can be done in one day.
Since it is such a long plane ride, I would combine it with something else you may want to see in California. We visited Palm Springs.
So to answer your question, I don't think that you would be disappointed as long as you realize that it is nowhere near as big as DW.
