Pros
Great salary and benefits. There is interesting work and opportunities to get to know and understand many aspects of the biotech industry. Sabbaticals and holiday vacation / time off is a great benefit.
Cons
Work activities are narrowly focused. You get a lot of great experience but it is often only within a narrowly defined area. Moving between other groups and organizations is very difficult. That is why many people stay within the same group for years. Senior management is focused on reducing headcount in South San Francisco. This is after they eliminated employees at their Nutley NJ and Palo Alto sites. This company is very much apart of the Roche group in that all the major decisions are made in Basel. I think Genentech's best days are over. Given recent failures, the pressure to reduce expenses will only increase.