Pros
Very flat organization -- no one is just a manager sitting separately. Team leads (known as "coaches") are actively part of the team, have deep domain experience. Treats people like adults -- you're expected to ask for help or direction, no micromanagement. Very loyal and supportive to employees, e.g. if there's a personal need such as illness or new child. Very open culture -- anyone can talk to anyone, no hierarchy. Great colleagues: only hires positive, decent, smart people. Creative environment: beautiful interior (there's a design & film group!), fabulous food, healthy snacks, great café, fun & interesting events, geeky/nerdy in a good way.
Cons
Management is opaque about business / finances, only indicates whether company is doing great, or needs to tighten for a bit (a couple of times during 14 years). No 401k matching, no profit sharing/stock (privately held). Hiring process is long & tough, but curious, smart people will thrive.