I think most guys who flew RJs for too long are committed to not letting any scope go. No matter what carrot is offered.
On the other side of things when we are talking about reclaiming scope, I can't stress enough how important that is to me. Had I been hired at United to fly a RJ, instead of at a subcontractor, I'd be sitting on over a dozen years of seniority, instead of two. If my relative seniority was unchanged, if my pay at mainline flying RJs was the same as it was at a subcontractor flying RJs, if I finally got to the Guppy at the same time, I'd have been at the top of the pay scale, instead of at the bottom, which right now is about a $300,000 difference over a career.
On top of that pay difference, I'd have an extra decade of 401k match. I'd have enjoyed better medical coverage, at a lower premium. I'd have been enjoying an annual month of vacation, instead of the two weeks I've been at forever.
Management can schedule any kind of airplane on any route they want. Really. 50 seaters kind of suck to ride in, but they fly ok. My bottom line: if it says United on the ticket, the people at the controls need to be United pilots. Pay should be as high as the Union can secure. But even if it isnominally less than what express pays, it is 100% worth it to the new hire who has to sit in the seat at that rate for a decade.