My transition to Delta was rough.
1st flight was DTW to BWI with a pit stop in CVG. The job site was at BWI. Got timed out in CVG, so overnight stay. CVG to BWI was an evening flight only, got sent to DCA and taxi'd to BWI. At least they covered hotel and taxi.
2nd flight was to DTW-JFK-POS (Trinidad). Delta misplaced my bag but it arrived on day 4 as I was leaving to the airport for the return trip. For 3 days of meetings and events I wore the same comfy outfit as i wore Sunday on the outbound- t-shirt, hoodie, athletic pants. I did laundry in the sink. I finally was able to buy a golf-style shirt on day 3.
NWA was frequently criticized, but during the ~11yrs with them I never had a cancellation, lost bag, or crazy passenger experience.
I tried Southwest for kicks once. Once. Also flew Pakistan Int'l Airlines twice. First class both times. Great food, ancient aircraft. It might have been a 757, it had a walk-up bar with mirrored backwall. No booze because Pakistan, the bar was used for storage. The seat ashtrays were mostly clean though.