Where do you want to live? That's your answer right there.

Considering a 20-30+ year career in the left seat, living in base is priority numero uno in terms of your health and overall QOL. Where are these short upgrade legacy domiciles that you speak of? Can I do this in a nice place like say, PHX, or do I have to slog it out in NYC?

MCO for instance is a game changer. There are no legacy domiciles there and the other majors (SWA/Jblue) have impressive upgrade times from what I've been told. MCO CA at Spirit is just under 3 years.