This question has been asked a plethora of times with a myriad of answers. PDT/ENY are very similar, approximately 6 years under current forecasts. PSA is much longer because they havea large group with the smallest percentage of flows. Envoy has a large group as well, but flows the highest percentage each year and, as another poster said, that decreases when they hit certain triggers. Piedmont has the smallest group, and the smallest number of flows, but we have an extremely high number of pilots with no intention of going to mainline and our flow is set to increase every time we hire a certain amount of pilots. PDT has the best pay, PSA has the best schedules.

Spend some time on any of the PDT/PSA/ENY/AA WO threads and you will see this reiterated many times.