1) You have the times now (or at least very very close) for Mesaba.
2) You will probably sit reserve for a month or two, three tops at Mesaba.
3) There is a reasonable shot at upgrade (as always, SUBJECT TO CHANGE) at Mesaba in the 2-3 year range.

I don't know much about Eagle. From what I've heard it is a decent place to work (except for the upgrade delays, which could also get better, of course).

Mesaba is a solidly OK place to work, and we could be on our way back to being a good place again. I know it is small praise, but there are plenty of places far worse to work at then Mesaba. We have pretty good work rules, somewhat lousy FO pay (although it is actually OK for Saab FO pay but terrible for Jet FO pay), and currently brisk seniority movement, hopefully keeping your FO time fairly short.

Good luck on your choice.