Pros
I enjoyed working for AST. Although their business spans the US, they found a way to help everyone feel included and working together. I didn't follow the typical contract process, as my employment followed an internship. Nonetheless, AST was quick to resolve the issue and I was cleared to work in a timely manner. The benefits are incredible and the staff is nice and welcoming. Everyone is very goal oriented and team focused. I loved working for AST.
Cons
Really, the only downside is that the company as a whole isn't centered in one office, but rather, they are designed to support contractors throughout the US. They do a great job bridging this gap by taking advantage of many online applications, but the distance still exists. So, if you are wanting a more personal relationship with your manager, you'll just have to work use technology a bit more.