Vantaggi
They gave me work at better than minimum wage. They answer the phone when they're open, even if it is just to tell you that they don't know, or can't help.
Svantaggi
They're highly disorganized, and you can not trust their spoken word. I was scheduled for a two night contract, which got extended to almost two weeks. One day at a time, always late the day before or early the morning of my requested extension. - Most often, not even extended by them, but by the contractor they staffed me to. Worse than that, they made an error in my contract, verbally agreed to fix it, but then later claimed to have never agreed on it. Basically, they robbed me of time and money - but had no problems requesting I do work well above and beyond the difficulty level of the original job listing.