Pros
Casual work environment. When there was funding, the work was interesting. Looks good on a resume - if you want to work here, don't plan to stay long. I'd recommend 2 years, max (if it remains open that long).
Cons
Questionable future - US Department of Energy funding has decreased over the past several years. Annual layoffs are now the norm. Lots of fiefdoms and horrible internal politics. Once you're labeled, it is VERY HARD to advance professionally. Upper management (i.e., the CIO) spends more time on re-orgs and seating arrangements than following through on major projects, several of which have failed miserably, and yet she still remains. In the "real world" an underperforming CIO would get ousted for this sort of poor performance. The average employee age is over 57. Many, many people are biding their time until retirement and are viciously clinging to their jobs. That is to say, these people only have their own best interest in mind and won't exert any effort to help another person grow professionally. Performance reviews are a joke. Sexual, racial, and other types of discrimination is not unheard of.