Vantaggi
It's a good place to start a career and you get exposure to alot of different companies. You get an opportunity to travel if you want to. But if you don't want to travel they will work with you to find engagements in town. This scenario is more likely if you are located in a bigger city. Not sure if this would apply for the smaller markets where Protiviti is located. Encourage their workers to gain certifications that are recognized by the industry. They will pay for the fees and books when you have successfully passed the certification exams.
Svantaggi
As stated earlier it's a good place to start a career BUT not everybody can have a career there. The culture is very much a carry over from the Anderson days - highly poltical -much like the Big 4 firms. Essentially if they like you and you fall into the right group they will keep you around and work with you. But if you are not fortunate enough to fall into one of these 'select' groups you are a marked man and you will always have to prove yourself. I believe alot of the leadership does not really have the experience as their title - majority of the top leadership are legacy Anderson. I am not trying to bad mouth Protiviti b/c I think it's a great place to start a career and gain valuable experience. But after you have gained the needed experience and decide to move out you will find that there are companies that will pay you what you are really worth, and there is a work life balance.