Pros
When there is a good contract, the money is good. Being a contractor, your time is your own. For the most part, the work environment is friendly and this is a great place for a people person.
Cons
Job can be 24/7. You as a contractor will take the brunt of problems and there is no compensation for work that is over and beyond the normal contract work. Have to monitor pay as there are often problems with invoices being paid accurately.