Pros
Fast places a lot of trust in the hands of its employees, and very early on. Each employee allowed to complete his/her work without micro-managing or direct intervention. There is an unofficial 30-minute rule, though. If you cannot solve a problem within 30 minutes, stop wasting time and ask for help. When help or guidance is needed, the more-senior employees (even the partners) are readily accessible and always willing. Fast has done a great job creating a team attitude, too. Fast throws one or two social events, with significant others invited, each month. The easy-going work environment is great for motivated, task-oriented people.
Cons
There is little unsolicited feedback about job performance, but this just forces you to be proactive if you want feedback.