Pros
If you are on a multi-year contract, then you will be safe for the time being. You will get to work with good people on your teams.
Cons
The cons are too many to list. The checks are not steady because I was not paid timely several times. The stated annual budget for training only exists if the client will pay for it. There are team building activities unless employees pay for them. Teaming partners were expected to do all proposal writing even though rates were changes after agreements were made in an attempt to win work by providing the lowest price. Speed is valued over quality. Teams too often have more work than they can handle and are not compensated for working more than eight hours per day. Lastly, executive leadership leads through intimidation, resulting in time wasted by arguments and good people leaving.