Mitch:
Re Mayacama, I guess "worth the billing" would depend on what the billing is. Is it one of the 10 best courses in our state? Likely not. But is it the best course within an hour's drive of Napa? Seems certain to me. But you're right in any case, a lot of what makes it great is what some would call the "experience" - caddies, very private, secluded, etc. Of course to me that counts, especially when someone is asking "where should I play", but I guess if you want to limit this to pure architecture, it wouldn't.
I concur re the others in any case. Just note re Chardonnay, they took one nine from the old private Club Shakespeare and it's now the front nine on a new 18-hole course, Eagle Vines. The other nine is now public, part of the 27 hole Chardonnay GC. All five of those nines are worthwhile to some extent.
TH