Pros
Growth company - hiring constantly so you can get a level of seniority very quickly. Relatively good pay/bonuses, frequent raises. Flexible working hours. Very geek oriented culture, no dress code to speak of. VPs wear jeans and polo shirt. Other employees seem to have bounced into their cubicle from a mosh pit. Excellent workstations, frequent computer hardware upgrades. They will provide you with the best tools for the job, and aren't cheap like other smaller or cash-poor companies. Great opportunities to interact with smart individuals. From what I can tell, the org structure is fairly meritocratic and generally speaking the best people move up.
Cons
Growth company - somewhat disorganized internal processes, poor cooperation between groups. The various departments are reminiscent of feudal kingdoms with managers fighting amongst themselves. No stock options given to employees as far as I am aware. Legal department has been granted ultimate powers after the NTP settlement and this results in a certain air of paranoia which I think could hamper innovation. Avenues for career growth seem inadequate. Despite continual external hiring the internal job board listings are anemic. Management has not sent any of the developers in my group on any kind of training courses. Office space is done in a dismal purple and facilities are pretty limited.