Pros
Excellent benefit package at a very reasonable price to the employee, much better pay rates than most (even for the same position, because all firms seem to be eating from the same trough), and generous vacation days are available. If you opt to take the benefits and the vacation, it will be reflected in your net pay, but SCI still offers the best benefit package I've seen in MANY years as a consultant. SCI pays a high percentage of benefit elections, so it's well worth taking their insurance rather than looking on your own.
Cons
It always depends on the worksite, whether consultants are well-treated or not, and Solutions seems to have good worksites for their contractors. However, there's always that "stepchild" stigma.