DL:
In Jan, DL changed flight times on us and gave us the option of staying overnight in ATL on our own dime or cancelling the flights. We cancelled and rebooked on AA.

In June, my wife needed award travel on short notice to go to BOS. DL had one flight for 50K; AA had close to 10 options for 25K.

We converted our relatively small amounts of SkyMiles to HHonors points. Doubtful we'll fly DL ever again.