VV, congrats on what are 2 of the top choices for airline careers, world-wide. There are many challenges ahead for both airlines, domestically and internationally. But without a crystal ball, it will be hard to go wrong either way.

I would make the decision based on QOL issues. Since you know you want to live in NH or ME, commuting will be a, if not THE, major player for you. I've never commuted along the east coast, but from my experience commuting out west, commuting for FDX is much, much easier than for the pax guys. I get an extra day at home on the front and back end of most trips, and with our double deadheads, it gets even better. For pax carriers, you will likely leave the morning before your day 1, and if off-line you are at the mercy of the gate agents, and on-line pilots bumping you. For FDX, with seniority that will take some time, your day 1, and last day of the trip, could be at home. If commuting on FDX, your seat is guaranteed and you are protected (maybe Delta is similar in that way, not sure).

Another QOL is dealing with FA's and pax. I don't miss it at all and wouldn't choose to go back to it, but it's not that big of a deal in the big picture.

Then, the quality of flying you'll be doing as well. Night hub-turning is brutal, but with the upcoming retirements and hiring, you should be able to move into better flying soon. As a commuter though, you will either hub-turn for longer on the 757, or be on reserve (crashpad) longer on a WB, than if you lived in domicile. The daytime flying at Delta will be better, although commuting into/out of it, will sometimes cost you an extra day at home on either end. Also, even though daytime flying is overall easier and more enjoyable, you'll end up spending much more time in the actual jet at Delta. I have barely broken 1000 block hours at FDX in 5 years, where I used to approach those hours every year at the passenger carriers I was at before. Bottom line though, night-time flying is tougher for most people, and we have more of it at FDX than they do at DAL.

Pay is a QOL issue as well. You can make more at FDX if you choose to go for the $.

I suspect you have a gut feeling of where you'd prefer to go, and no matter what you read on here, you will end up going with your gut.

Good luck with the tough choice and congrats!