Only Envoy has a true flow...the rest of the WOs that advertise a path to the majors have preferred interviews...which is not bad, but it's not a flow and preferred interviews are even a more tenuous perk that can be snatched back.

PSA was a great place to go for DEC, fast upgrade and a path to AA about a year ago...now that is all turned to crap. With the majors picking up their hiring everyone is going to likely get to a major long before they upgrade or flow or get their preferred intereview just because those interview offers are going to come much faster to everyone.

So...pick the airline that gives you the best QOL first the rest will likely come to you as the desperation increases.