Pros
Faction has truly remarkable people and a fantastic culture. It's one of the most creative, hard-working, funny, intelligent group of people I've ever worked with. Group lunches are pretty much a weekly occurrence on Fridays, and the agency tries to organize full-company events for people every few months. You will always feel like you have friends here, and they're definitely a weird bunch of people (in the best way possible). They also always produce fantastic work. You can count on your coworkers here to set the bar very high and hold everyone accountable. It's what makes us all feel proud of the work we do at the end of the day.
Cons
Faction is a great place to be until you want to advance in your career. Directors have no budgets for training opportunities, so don't expect to go on any learning trips or conferences. Promotions are an even less attainable concept. The mentality seems to be that those things don't matter, or that they're likely to make you more valuable to other companies (which is a completely broken way to think about management).