Adlerdriver

Living in MEM or commuting would be a huge factor in your QOL. Living in MEM and sitting reserve has potential for good QOL (but, you're living in MEM and that's another discussion). However, assuming manning continues to be an issue and hiring stays slow, I think life on reserve will be busy. But, even so, if you decided to move there, your life on reserve in domicile would be acceptable.

That said, the reserve system at FedEx is one of the worst in the industry. Schedules range from your entire month's R-days all in a row to 2, 3 or 4 groups of R-days across the month. 12 hour reserve periods have a mix of night, morning and afternoon start times with the nights going junior. Call-out is 1.5 hours from phone call to show time (with an option to drop that to 1 hour if you can make it). You can put yourself at the top of the list based on seniority if you want to fly. Beyond that, you have little to no control over what happens to you. There is no bypass, no long call, no ability to pick up trips on your R-days, etc. Massaging your schedule via moving R-days or outright dropping them to pick up trips has been (and probably will continue to be) very difficult.

Very junior pilots will probably be unable to hold published reserve lines and be awarded secondary lines. These can be built with uncovered trips, R-days or a combo of both. You find out your schedule for the upcoming month 5 days before it begins. My experience with these was reasonably positive simply because as a commuter, I wanted one big block of reserve and they gave it to me on the days I wanted. The more complex your desires, the less likely you'll get anything close.

There will be a mix of short notice trip assignments and longer 12-18 hour notifications for known uncovered trips. My experience was the longer notifications were more common but YMMV.

Senior lines on the 757 consist of week on/week off flying with city purity (flying to the same destination every night). Conversely, the junior lines have less of a pattern with a "shotgun" burst of trips across the month.

Junior pairings will have multiple legs in/out of MEM each night. An example would be a ~0400 departure to COS then on to GTJ, 12 hour layover and reverse routing back. Upon arrival to MEM at about 0030L, after the two legs inbound, you may be on your way to do a similar trip after a couple of hours sit. Another junior pairing would be the am out and back. 0330L departure MEM-FSD-MEM

It's been a while since I've been based in MEM but I think what I gave you is a reasonably accurate hack at what you might encounter. Maybe some guys with more recent experience will chime in.