Pay is lower than private sector. I ended up leaving for a 30k pay bump. This means there are very few senior engineers with 10+ years experience.
During my 8 years there was a shortage of engineering leadership. There are always manager positions they need to fill. If you handled yourself professionally and wanted to be a first line engineering manager, you could get there in 3 years. Most engineers don't want those jobs because of the nonsense you have to deal with.
This organization has way too many meetings. Some days you go from one meeting to the next, at each one getting asked why you aren't done with your task. "Well, sir/maam, I've been in meetings all day. Hard to get anything done this way."
Environment at 76 PMXG is reactionary. A lot of knee-jerk reactions and in some departments there seems to be an "emergency" every single day. In general, the production managers are good ol' boys and just about all of them got their position because they know someone. This means they make a lot of poor, short-sighted decisions that engineering has to deal with.
There is an incredible amount of red tape to get used to. Get ready to fill out a form, turn it in, and when you go check on it a couple weeks later you get told that there's an updated form and you have to start over.... get ready for that kind of nonsense at least once per week. Expect a couple months to get hired on, and anything you order to take 1-4 weeks to get in your hands, and any major project to take twice as long as it should.
As with all Tinker jobs, you have to deal with the gate line in the morning. Parking outside B3001 usually isn't too bad but it's an adjustment if you've worked at a regular job.