Great place for young engineers, not so good for the 9-to-5 types.
Pros
In my second year out of school I was designing flight hardware for the Dragon capsule. As an engineer, you get involved in all aspects of your product from design to manufacturing to integration. This is a great place to cut your teeth as a young engineer. Unfortunately, your experience will vary greatly depending on which group you join; not all managers are created equally. Some are great corporate politicans but mediocre engineers. Some know how to get large bonuses for their reports, and others don't. People who like to do things by the book and have everything neatly tied up won't fit in here. You have to accept that everyone is rushing and often shoot from the hip; sometimes the documentation is sloppy or someone makes a mistake. If you don't have the patience to deal with it, you won't last long. ULA is screwed. We will eat their lunch sooner or later, I guarantee it.
Cons
You will probably be somewhat underpaid. Benefits are mediocre. You get thrown in the deep end, sink or swim. There is no hand-holding around here. Often times a square peg is put into a round hole because we just need someone to do the job, and then the hapless assigned person is stuck with it forever.
