I know nothing about the quality of the philosophy programs, so I'll restrict myself to the areas.
Davis is a small university city in farming country. It's quieter, and cheaper, but it get cold in the winter and hot in the summer.
UCLA is smack in the middle of the hippest parts of LA. It's expensive, crowded, and has lots of traffic, but there's a lot to do and it almost doesn't have weather.
FWIW, I interviewed at the biology department at UCLA in March. They put on a great show, making UCLA look like it guaranteed a career and was a lot of fun for graduate students. Several grad students told me "It's not just a show, it really is a lot of fun here. That's why I've been hare seven years and I'm not done yet" :-)