Pros
I have worked as a graduate student researcher for a little over 4 years, and there are a lot of things to like about UCLA. The campus is great, there are a lot of smart people to learn from if you look, and the competitive environment of Neuroscience really pushes you to be productive.
Cons
I don't know exactly where the kink is, but I have been double or triple paid several times, which seems nice but then the school sent all the notices to my first year address, even though I had changed my address through the main UCLA student web portal. Turns out the grant people keep their own addresses and don't update; they were attempting to go to collections against me when my adviser found out and obviously I got things settled. It then happened several more times (although obviously contacted them immediately later). On other occasions I have gone without pay for 2-3 months at a time, just to have them pay out all that money at once. Its EXTREMELY annoying as a grad student who doesn't make that much. I have other less direct evidence of the ridiculous inefficiency of UCLA's bureaucracy but its more hearsay. Just be ready for it.