I worked at DOJ Antitrust Division full-time (More than 10 years)
The Division offers a very responsible work/life balance.
Investigations tend to be of very long duration.
I applied through college or university. The process took 6+ weeks. I interviewed at DOJ Antitrust Division (San Francisco, CA) in April 2011.
Very informal / conversational. Not that bad, but hard to get an interview (the DOJ gets a ton of applicants, and vets get first dibs). Once you get an interview, your chances go up dramatically. You also have to pass a drug / background test.
No negotiations. Take it or leave it offer.