Just came back from SFO to IND roundtrip and was mindful of the 50/60% loads. It was nice for me(i.e., elbow room), but it does raise the yellow flags.
I took my first trip on Southwest a couple of weeks ago and was impressed. We changed our departure time and airport for return...and guess what??? A $3.00 credit for lower fare. NO dings of $100.00 for changed schedule.
I think Delta ought not to be surprised when it happens - sad as it will be for many very good employees.