Pros
They have a refreshingly involved work ethic, which has been hard to find in my experience with outsourcing companies, and the clients seem to be super satisfied as well. Their project managers actually care about the work being done and they keep tabs on the progress. You essentially get to be a part of the client company's team.
They also seem to be experiencing healthy growth as of right now, which is a good sign.
Cons
The client is always the first priority, you are merely a contractor. You might forget it at times and feel like an employee, but it is what it is.