Pros
Great people, tools for learning, opportunities for growth and advancement. It was great to be a part of an agency that has team members for dedicated areas, from digital (social media), implementation, QA, SEM, SEO, design and development. You aren't wearing multiple hats, unlike start-up/smaller agencies.
Cons
Processes are constantly shifting and organizational restructures occur at least once a year. People who get promoted to managers don't seem to know what they're doing. The company is in another "growing pains" phase, exploring other software and project management tools, hiring executives for every department, which isn't necessarily bad, but don't get comfortable when you finally get in the swing of things. Burnout can happen very quickly. Perhaps pumping the brakes with new business for a short while can help everyone catch up and move things along and launch more efficiently.