For the Hyatt in Indian Wells, its true that using a suite upgrade wont give you a villa guaranteed. You'll get one of their suites for sure (which are still VERY nice), but often for Diamond members, they do upgrade to Villas (even without use of a suite upgrade at times).
At the Century Plaza, I used a suite upgrade, was given a "Century Suite" and its a very nice room with a great bathroom as well (its 1.5 baths).
Be warned about both the Andaz in WeHo and SD... they are party hotels. Going to be lots of young, drunk, early 20's there, especially on weekends. If thats your thing, great, otherwise, I dont really recommend.