Vantaggi
You can go to sleep at night knowing that, even if it's in a small, indirect way, you've contributed to improving the health and quality of life for many people. The benefits package is outstanding. If you live in SF, commuting is a dream; the Parnassus campus is right off the N-Judah, and UCSF offers free shuttle service to its other sites.
Svantaggi
The biggest downside is the culture--- behavior that would be unacceptable in a 3rd grade classroom is tolerated here. I've worked at two other academic hospitals, and I find the abuse by physicians (toward staff) at UCSF to be shocking. Very little opportunity for mentoring or professional advancement for administrative/nonclinical positions. There is no incentive for bright, educated staff to stay beyond two years--- the benefits ARE terrific, but salaries are too low and not competitive. It breaks my heart to see UCSF continue to lose bright, talented folks, while holding onto the deadweights (who know that the bureaucracy will protect them forever). Labor Relations offers no support to managers. If you're interested in working in a school of medicine, look to Stanford. If you want to work in an outpatient setting, look to Sutter (CPMC).