Dallas is going to be slow for a new hire in either example. I just took the ORD vacancy on the 175 out of DFW and my bidding seniority went way up. I have several friends who are FO's on the 175 and they are still sitting reserve after several months.

From what I can tell listening to new upgrade Captains on the 175, they are on reserve but being flown a lot. Hopefully this new upgrade cycle will ease the pressure on them.

Sorry I cant speak much to the other airframes. QOL I feel depends the most on where you live. If you live in Dallas and have been an FO for a bit, sitting reserve on the 175 will keep you home a lot. Plus you can bid TDY for ORD while it lasts and get all of those perks.