Pros
GSA allows a good balance between personal life and work. After 1 year of working there most people are allowed to work at home 1 day a week. You can choose alternate work schedules, say 9 hours a day and get every other Friday off if you want. GSA will also pay part of your commuting costs if you take public transportation. Management is very supportive and if you try hard you will stand out among the crowd.
Cons
You work with alot of people who have been in the government for a long time. They don't work too hard and complain alot about small issues. They have no experience in the private sector and don't realize how easy they have it. They don't embrace change. Once you reach a certain Grade level it is very hard to move up unless you are favored politically. But that is almost every organization, isn't it?