Pros
Personally, I had a wonderful experience at AWA. As an intern, I was quickly assimilated into the team and was made to feel comfortable giving input to the design process. Everyone is incredibly warm and friendly, and the office culture can't be beat. For me it was an opportunity to focus primarily on one aspect of a project and refine my skills in that area. That being said, it was a relatively short period of time, and if I were to have stayed longer may have resulted in being pigeon-holed into a very specific role. I was able to keep normal hours, with only the occasional late night or weekend spent in the office.
Cons
It seems that interns' experiences can vary quite a bit. It very much depends on who you are working directly under and the phase of the project. Also, compensation for interns is in the form of a stipend which is quite low.