I was senior to you and left to be a commuter. It was a really hard decision, but it has been the right choice, so far.
Also, I have yet to meet anybody that has left NJA for a major that regrets it.
I would imagine the decision is about the same as the decision to leave a spouse/GF. It's a comfort zone. They said they would change. Is it really that bad? What if I don't find anyone else (Furlough)? Then, you get the courage to do it. And, you realize that they weren't changing, and there is better out there.
27 years is still a long time in this career.