If your jr the 757 flying sucks, it's a lot of 3 day pairings back to back (6 day work blocks) worth 15 hrs each, when you could do one 21-24hr 4 day on the 737 for the same pay. The 737 has a lot more variety and quicker upward movement. I wouldn't want to be a bottom feeder on the 757. Commuting to reserve is not that bad with aggressive pick up, I wouldn't move to a base unless you really want to live there, your time on reserve will be short lived. 737 has a ton of different trips and a lot of open time, great for new hires. Fun plane great crews. 757 is great when you can crack 50% or better seniority and hold the good trips, but any of the international stuff I.e. 757/777/78 is really fatiguing, not for everyone. A lot of guys are parking on the 737 to avoid the all night long haul flying, and if you work the system on the 737 a little the money is really great. Probably more then you wanted to know