Pros
Smart people, most of them holding graduate degrees. Managers, even several levels up the chain, are usually friendly and generous with their time. Telecommuting is generally allowed at least 1 day a week, although this varies from one group to another.
Cons
Limited advancement opportunities - I once asked a mid-level manager how one could get a promotion and he looked me in the eye and said "know somebody". Sadly, my subsequent experience at the company seems to bear that out. Annual raises tend to be rather small and there are few opportunities to learn new skills. Management can make some rather "Dilbert-esque" decisions. It often seems that the product release schedule is dictated by the usually-irrational promises made by the marketing and/or sales departments rather than logic, resulting in fairly frequent crunch-time scenarios. This in turn leads to product quality suffering and unnecessary levels of stress. The food in the on-campus cafeterias, while good, is not free, nor is it particularly cheap. The engineers work in drab grey cubicles under cheap fluorescent lights.