Pros
Lots of hands-on experience. If you work hard and are smart you will be given a lot of responsibility and trust. They give people opportunity to move around when/if you want. Frequently hire interns for full time positions after graduation. Fun place to work, young and innovative environment. Overall the people within the company are smart, talented, hardworking and fun to work with. Some teams, however, are definitely better than others.
Cons
Management needs training, they do a poor job of fostering talent. No mentorship whatsoever. Very young and at times immature workplace. Lots of drinking/partying, so if you have problems with that, this might not be the place for you. Salary range wavers person-by-person and compensation is rarely fair. If you want to grow you have to be aggressive and proactive about it. They will, however, pay for classes and conferences.