Pros
This is a great hands-on place to work if you can't find employment elsewhere. You can get experience at world renowned companies that you can't get anywhere else. This company is a stepping stone into a career. I especially recommend it to recent college or high school graduates.
Cons
The biggest downside is the complete lack of benefits. They claim to offer benefits, but they are so terrible that they're not even worth it. There are no sick days and only 6 vacation days per year, but they are so hard to get you almost never get paid for them. You must take no more than 5 days off in the previous 6 months and that may not be possible, depending on the site you work at. Some sites close down more frequently than others. It was also implied to me that I could be hired at my place I contracted. Don't believe them! After 2 years of working in the same position I know its not true. Other advise: If you want a raise, request it. This company does not want good workers to go, but you have to go to them. Any incentives is like pulling teeth. Be on top of it.