Pros
They treat you well. There are many perks to working with FAST. Office Culture is great. Since you are moved around often your FAST friends become like family and everyone in the office is usually very open to including new recruits in their outings. Great pay. Great benefits.
Cons
You move a lot. You never really ever establish a real HOME with FAST. You don't get to pick where you want to go. Taxes are just boring. There isn't much of a career ladder to climb. You enter and work for a supervisor. Then you become a 'lead' and then usually that's the end of the road unless somehow you become a Project Manager but you have to be around a really long time for that. You work a ton of overtime. Some weeks turn out to be 60-80 hour weeks. They do give back to you for that though.