When you get assigned your equipment and base at Mesaba varies. On average, you don't find out this information until as late as the first/second day of ground school.

Most people in the Saab that I have seen get based in MEM first, however vacancies are published very often, and most are awarded their first pick duirng simland.

All CRJ-200 spots are currently going to be based in MSP for now, and the first several CRJ-900 spots are also going to be in MSP (in the future, DTW will have the most -900 bases).

As far as reserve time, it is virtually non-existant with the flow of things around here.