Pros
Cheap hotel deals, when available, are a great benefit (only for permanent employees). Comfortable office building. Tries to be green, if you like that kind of stuff. Traces of corporate loyalty remain, but that's changing fast, so hurry up to enjoy it. They have money to burn on nice HQ facilities, which is nice for us who are there. Company makes good profits, so great bennies and pay for upper management if that's where you're looking to work.
Cons
IT outsourcing is well underway. Beware if you are IT contracting; they might tell you it's "just a re-org", but IT employees are being rebadged with outsourcers later this year, or (mostly) just sacked, with only a handful left to oversee the outsourced services, and IT contractors have no idea what's coming. Outside of IT, seems OK, so long as you watch for the next benefit cut; they do this to some random thing every year or so. Other IT shops in DC Metro often pay much better. Absolutely, totally would never recommend this place right now to an IT friend unless s/he is desperate and willing to work a rapacious contract but with an unknown future.