Pros
Benefits are really nice, especially the pension. Your job is pretty safe- you have to really do something bad to get fired. Work/life balance (for me) is ideal, but I know of some people who work a lot/take stuff home. The pay is decent. I like having separate vacation and sick pools, as opposed to the more common PTO policy.
Cons
Oh boy. Well it's hard to move up or around unless you know the right people. If you don't, you'll be stuck in your position for a long time. Having to work strike duty (again unless you know the right people) is a bummer. HR here is shady (creating positions for people who complain they want more money without posting it for everyone to apply for example). The programs we use are SUPER outdated- it's frustrating. No work from home (what year is it?). If it's snowing and you can't get in because SEPTA's down, you are forced to take a vacation day. Some of the managers here are terrible, though I guess you get that anywhere.