Pros
You will get to work with incredibly talented individuals who really do love their job and also you will get to work on some of the greatest games in the industry. The culture is a positive for most and I feel like they do treat those who are talented well and try to keep them satisfied. Over the years change has been frustratingly slow sometimes but I feel like leadership is taking the company as a whole (together with all R* studios) in the right direction regarding employment, hire/fire and technology. Despite the work conditions I do feel like management is very understanding and relatively open, but of course there are politics.
Cons
AAA game development culture in general favors overtime, crunch and stressful environments and R* San Diego is probably the worst. There will be a lot of mandatory overtime and not a lot of time for home or social life. I've seen several divorces, relationships fall apart and socially inclined employees get burned out. Some people just flat out resign due to the missed time at home. There also seems to be some resistance to change not only with work ethic but also technology.