Pros
A place to do top-notch scientific research that also directly impact people's lives A shared sense of mission and inspiration - to create medicines for unmet medical needs. Science driven culture - scientists truly enjoy a lot of independence, respect and freedom to publish. Genentech attracts really good people and in particular, the brightest scientific talents. Excellent perks - great cafe and day care, club house, free sports club membership, beautiful campus by the bay, Friday parties, retreats (and the list goes on). Genentech has a great reputation. A great learning environment: top scientists and vendors come to give seminars regularly.
Cons
Promotion and career advancements are very rigid and difficult. People are often trapped in tracks or positions with limited professional growth (if not impossible). It is not unusual for good performers to go 8-10 years without a single promotion. People are 'demoted' when coming to work for Genentech. For example, senior scientist becomes associate scientist; director becomes senior scientist. The pay is good but cannot keep up with the high cost of living in the Bay area, particularly for new comers. Merger with Roche basically capped any potential future growth. It is questionable whether its unique, science-driven culture will remain after the Roche merger.