Pros
1. The people, hands down not just nice people, but they really care about not just their coworkers, but also their clients. Everyone is so dedicated to doing what's best for the client and values their relationships with their clients that it creates a motivating and positive environment. Never do I think I've met such a great group of people who are so in tune with each other and committed to the same standards of service.
2. The environment. There's definitely some of that laid back California style here. While everyone is professional and at times stressed by deadlines, overall everyone is relaxed and comfortable with each other and together creates a great environment to concentrate and get work done, with just the right amount of fun in between.
3. The work. Maybe I'm bias because I love the type of work that comes with working in an agency, but I find that the research and hard work that I've put into client projects is rewarding and totally satisfying to see it come to fruition.
Cons
It can get pretty stressful around deadlines, but it's my impression that that's the business we're in. All projects are going to have deadlines, and since everyone cares so much about sticking to them so that clients aren't disappointed,