Here's an example from today at LGA (America's #1 Third World Airport) - Frontier flight to DEN scheduled for 4:30, pushed away at 5:15, par for the course on a storm day, but currently 1-1/2 hours later have still not taken off and in fact are now returning to the gate to refuel. Meanwhile, Delta's 5:15 flight to DEN (also an A320) took off nearly an hour ago, and United's 5:20 flight to Denver has been in the air about half an hour.

In short, I am feeling less and less ambivalent about letting my status with Frontier lapse next year.

Edit: For the record, the Delta flight left at 5:55PM, Southwest at 7:50PM, and the Frontier flight at 10:05PM.