I've never worked for them, although I did go through their application process.
The one I went to had a wall with a glass window separating you and their office. You were not allowed past the vestibule and had to fill out the forms on your own with no one really available for assistance. It was very cold and unwelcoming and made you feel like cattle.
I prefer Randstad, they have a much more warmer working relationship with their employees. They don't like to use the term "staff" or "temps", they refer to them as "talent" So they are like your corporate talent agents. The company is based in Amsterdam and has offices across the US. It was a fluke that I signed up with them but I liked them so much I went back to them when I wanted to change industries after 7 years on the permanent job they found for me last time. I registered at 3 places Kelly and Randstad and Olsten. Kelly offered me a collections job on the spot and when I declined it they never called me back, Randstad kept me so busy that every time Olsten finally called me I was already on and assignment with Randstad.
Olsten is half way between Randstad and Kelly, Most of the people are in the back, but they have one or 2 people out front to work with you so you are not completely isolated. Their lobby is nicer also, plants, nice tables to sit at while you fill out paperwork, but Kelly was a cold beige glass windowed jail cell.
Randstad is a littl artsy in their office design. I liked that.