If you're in your first year, and don't feel like DAL is the right fit, now is probably as good of a time as it'd be in a while. If UAL will provide you a better QOL the risk is worth it, if you're not too deep in at DAL. I had a person in my class that left DAL 4 years in to come to UAL. So these things happen.

Sounds stupid, but a pros/cons spreadsheet. Talk to your wife/SO.