Pros
SUN made it easier to gain access to a job that would have been difficult to get on my own. The process for getting hired was extremely streamlined - they didn't even interview me. I'm not sure if that's the norm (or a good business practice) but the offer was extended to me on a Thursday afternoon and I was working by Monday.
Cons
There is little to no communication between SUN and it's contractors. It's very difficult to get anything addressed unless they initiate the communication. There is no discussion of future projects/career development. That is the nature of companies like this, however, retaining good employees for future work should be the goal of any company.