Envoy's upgrade time just dropped from 8 years to 6 years and is continuing in that direction. Whatever wholly owned you pick, look at what upgrade and flowthrough will be for you hired today. Not someone hired 2 years, 6 years, or 10 years ago.
PSA is saying its 8 years to flow for a new hire and Envoy is saying 5.5 years. PDT says 4 years but they get that number by first doubling their pilot group, which then doubles their flow. We all know that's not going to happen in this hiring atmosphere. Envoy and PSA give more accurate and realistic projections based off of current number of employees.
You have the right idea about looking at quality of life. Just give a thought about the differences in flow also.