I have stayed at 3 Marriott resorts in California: Newport Coast Villas, Desert Springs Villas I, and Timberlodge. I absolutely loved Newport Coast Villas. Beautiful architecture and decor, in a fantastic setting, with exceptional access to both Newport Beach and Laguna. Awesome swimming pools. Great grounds. Beautiful sunsets over Catalina Island. This one is a winner.
Timberlodge is also a great resort. It has a very nice mountain lodge decor and is well located in the new Heavenly base village in South Lake Tahoe. The villas are a little smaller than many Marriott resorts, there is no view of the lake, and the surrounding neighborhood is a bit congested...but it's still an appealing place. Timberlodge is very comfortable, and it is the nicest timeshare resort in Tahoe.
The grounds of Desert Springs Villas I are gorgeous and the villas are huge, but our villa was in a sad state of repair and was not overly clean. Many people like the fact that guests at this resort have free spa access at the adjacent Marriott hotel, but I would stay at the newer Shadowridge or Desert Springs Villas II rather than DSV-I on a return trip to the area.
All in all, I think Marriott is a great choice in California. It would be nice if they had a resort in Santa Barbara or on the coast in Northern California to go with their present locales, but maybe the future will bring more California locations.
Steve