Pros
You can network with actual professionals in decent companies that Milestone contracts with so that you can hopefully get a decent job later. Other people in the same boat as you on teams at the company are almost all pretty cool.
Cons
Management is completely out of touch with reality and have no idea what the teams they build actually do. Senior management constantly makes promises to clients without being able to deliver with current resources, at the detriment of their teams, then passes blame and accountability to the lowest tier teams so that they don't have to take responsibility for their lies. Entire teams get terminated at the flick of a wrist just to save the company a few bucks. Some teams (with all full-time permanent employees) have recently been told they have to move literally across the country at their own expense, or their job ends after the new year. Milestone isn't even offering severance pay or any kind of assistance. HR doesn't care about you, your family, or anything. They break the law CONSTANTLY, just hoping you won't go to the DoL against them. A few people do, and get money out of them, but I guess that breaking the law and only getting caught every once in a while is still profitable ultimately. Pay is absolute crap, as are the benefits. Salary is usually 20% or more below local medians for different job titles, but such is life in a contracting company, I guess; however, you'll literally never get a raise because management doesn't do performance reviews or care. Unless you're good at counter-manipulation to get in with the cliques of the company, you'll also never get promoted.