Commuting: Ditto the dbl dh city pair purity near you above. If you have to MD it, the single departure 12 dayer can work good too. Some guys say "if you're away, you're away," meaning it doesn't matter if you're in ALA or ABQ. If you can get a 12 day single departure with a dh on either end you may be able to shorten it by a day or so with a jumpseat or immediate return.

Non-commuting: Of course, you can live in MEM and bid reserve in MEM and hope scheds doesn't abuse you..... and some months, they don't, but when they're short on crews, you get called. Each individual has his/her preference on RA v. RB. Personally, when I was junior I bid RB and commuted to it.

Bottom line: as stated earlier, the key is seniority, no matter the seat or equipment. After that, it's part preference and part equipment.