Pros
Quirky culture, great sense of community and mission, generally fun and intelligent co-workers, lovely ocean views from many of the windows! It is very easy to switch functions within the company, and both research and business personnel are top-notch. People take great pride in their work, and managers understand work-life balance--Genentech is notoriously mom-friendly.
Cons
There is some sense of disconnect between the goals of business units and research department--some brand teams have very poor scientific understanding of the products that they are working with, while certain researchers are only vaguely aware of marketing as a function at Genentech. Compensation is not competitive with some of the other biotechs, but this is generally made up for in generous benefits. The company's growth and expansion has led to the erosion of former "small company" and entrepreneurial feel, and the instability of the upcoming Roche takeover makes everyone uneasy. As a new hire, it can be unclear of what the promotion schedule is like, and some departments are very hierarchical.