You'll be working with incredibly talented lawyers who care a lot about the work they are doing

Terrible pay, frequent hiring freezes, a certain amount of bureaucracy to wade through

It helps to have an internal referral - although it's a federal agency, lawyers are hired using excepted service, so there is a lot more leeway in hiring than for other civil service jobs, but there is also lots of great talent competing for the same positions (all of my bosses went to Harvard, Yale or Stanford Law)