Pros
From day one, FAST treats you as a person not a number. I love the small company/community feel. You are given a lot of responsibility right away and your ideas are respected. The job itself is fun, challenging and not monotonous. I've been able to impact departments and individuals in a number of unexpected ways. Benefits are good and you are compensated based on what you contribute. Throughout my career with FAST it has been very apparent that when you work hard for the company, you get the same in return.
Cons
There can be a significant amount of overtime as it gets closer to a rollout date. On a positive note, there is additional compensation for anything over 40 hours. Some people also view having to relocate as a drawback. This was actually a huge plus for me. I have a family that was used to me traveling for my previous job. They love having me home at night but moving every 2 to 5 years definitely isn't for everybody. FAST does pay for relocation and do what they can to make the transition as smooth as possible for its employees.