Pros
I worked at IQ for almost 4 years, which in advertising might seem like an eternity — but I enjoyed every minute of it. IQ is a place that encourages individuality, smart thinking, and creativity. The business itself is doing better now than ever I believe, which I credit to smart hiring and a better understanding of the market position of the agency. There's a all-for-one/one-for-all mentality at IQ that almost polices egos and in-fighting. People at IQ really collaborate and aren't looking to jump over each other for glory or control of a project. Though IQ has always been known as a good agency, it is far better today than when I started, which is a great thing for anyone who is considering working there or working with the company.
Cons
As with many agencies (and brands now for that matter), turnover happens. It was common at times for people to leave and for work to be spread around instead of re-hiring for that position immediately, causing some tension for people that became over-resourced. Work is sometimes resourced from the top down instead of spread amongst teams with differing experience levels, with upper level employees keeping a more dense schedule while lower level employees may have significantly less work or exposure with a client. Some of that can be attributed to being a smaller agency, for what it's worth.