Pros
The relaxed atmosphere and relaxed dress code were the best parts when I worked there. The people were very friendly and the type that you'd hang out with outside of work even (which isn't common in the tech industry, and I've worked at a few). There's some interesting reviews on here that I don't tend to agree with. I worked there for almost 2 years can honestly say I had fun doing it. The most I got out of my employment, I would have to say, was the exposure to different aspects of the industry - given that we were often asked to collaborate with each other to come up with new ideas. It seemed like everyone's input was taken in to consideration, and I really wan't there that long.
Cons
I'm going with 3/5 stars on the 'Work/Life' balance for a good reason, and depending on your position with them I'm sure this could go either way. There were times that several of us stayed up late to finish things or finish a push to a production environment, but it wasn't often, and besides - it was like we wanted to (or at least I did?). Everyone has a responsibility and the trust and depend on you, which sometimes can be 'con' I would say.