Every FO I have kept in contact with that has left is very happy, and I am happy for them. I have seen quite a few FOs turn into shells of their former selves here. Management is too stupid, and way too uncaring, to see the abuse that the younger guys have taken.
Several FOs who have moved on say they wished they had gone corporate or just done the regionals for a year or two and move on to cargo - many of their friends did and are in the same spot or better than they are now.