Pros: lots of freedom in the way work is done, good professors, intelligent and enjoyable people.
Cons: high pressure, very large workload, low pay.
It was graduate school in a hard science. It was a 60 hour work week with responsibilities to many different bosses. In a typical week there were dozens of hours of homework, grading, and research to do, as well as many meetings. It was an enjoyable atmosphere with many intelligent people, and incredibly rewarding and interesting work. It is however high stress. There is a large amount of pressure to perform, and a very large work load.