This is often of critical importance when deciding between rival job offers. What have you heard about the companies concerned, do you have friends or family working for those organisations who can give you a real insight?
Don’t just think about salary, as a company with a poorer reputation may seek to offer a higher salary to cover up for its weaknesses in this area.
Tip: Why not call both companies and ask if you could visit the sites again. This will give you an invaluable opportunity to chat with staff and get another feel for the environment rather than simply relying on your experiences in interview. If one of the companies refuses your request then this may tell you something about the way in which they work.