Vantaggi
Randstad is a company built with a solid HR backbone. They have incredible training and are extremely systematic. Benefits are outstanding (a great employee stock purchase program in addition to the health benefits). As of this writing, you get 18 days of Paid-Time-Off (PTO) which can be used for either sick/vacation/personal days. That number rises with your tenure in the company. It's a great place for your 1st or 2nd job (their training will make up for lack of experience).
Svantaggi
When I joined Randstad, the company had a very entrepreneurial culture. Since that time, they have altered their leadership style and now micro-manage almost all aspects of the job. If you operate well in a structured environment, you'll be fine. In this company, promotions go to those who follow orders (without question). If you enjoy achieving results, but want the freedom to follow your own path in doing so, it's best to find another potential employer.