As you may recall, I had appealed the 2010 valuation of $11899 for a gold NCV week. I didn't go to the appeal session, as it was at 9am in Santa Ana, which meant I would have had to drive rush hour and pay for parking, and that frankly wasn't worth the savings I might have made.
I did file the "informal revaluation request" last January. I don't know if that helped, but I received notice today that my weeks are valued at $8000 for next year. That will save a third off the taxes.
I bought these weeks before construction for about $19k each. This winter, they were going for $4000-9000 on ebay and Redweek, so I consider the assessment fair enough.
You can appeal your California assessment between now and September 15; see the county assessor's page for information. You'll need some verifiable data about the value of your timeshare in the first quarter of 2010. The hearing probably won't be until next year, and you'll have to pay the tax in the meantime.