Avantages
Stable job. Pay is bad in absolute terms, but decent for a fresh graduate living in a low cost of living area. Coworkers are generally nice. Management is generally reasonable. Very open to flexible work times, remote unclassified work, etc. Note that Owego was molded by ex-IBM people from Endicott. They imported that culture into Lockheed in Owego when IBM pulled out and Lockheed hoovered up the workers. Other sites may not have this same culture.
Inconvénients
Pay is bad in absolute terms (or relative to e.g. Facebook). Programs are stable, but boring and old. Tech stack is old. Advancement is very slow for individual contributors; it's a bit more open for management, or "movers and shakers." Benefits got nuked by Obamacare shortly before I left.