A friend and I took his Acura MDX with it's built in nav system to Santa Barbara... While I just simply had it on, following along, it stubbornly insisted I was attempting to drive into the ocean when I pulled onto Stearns Wharf to park, and continually pleaded with me to make a U turn!
For the greater part, I'm with Mark (e57) on this... Thomas Guides will get you to 98% of the places you're looking for in CA. Newer developments are the only place they seem to fall short on (At least in the Orange Co editions) Nav systems are a novelty to me until they come down in price
