Pros
The opportunity to work on global communication issues with big clients and local issues with non-profits provides a wide range of experience opportunities. The emphasis is on highest quality work, not on where the work gets done. You can work from home and no one is on your butt about making it to the office by 8:30 or leaving before 5p. Big focus on the future of the business provides lots of room for young staff to stretch themselves. New office is really cool. Walking treadmills, playroom for your kids if you need to bring them to work for a few hours.
Cons
Its an agency, so pay will always be lower than a corporate job. Everyone juggles multiple client accounts so don't seek this kind of work if you are looking to just hang out and work on one thing. Pace may be too fast for some. If you are not a strong writer, this might not be the place for you.