As with most things, it depends. Are you flying into/out of hubs? Are there tons of rebook options available? Or are you in or out of a small airport, with minimal rebook options? Personal or business travel?

I used it a couple years ago for personal travel right before Thanksgiving. We live in a smaller market, nearly everything requires a connection, and we were flying to another small market. Used the Freebird rebook on the way home, the Wed before Thanksgiving. United got us to Denver 3 hours late...... And the only rebook they could offer was on Saturday. Freebird put us on Delta (so another connection....) but got us home the next day.

Freebird also has live people who text you, and sometimes they are pretty witty.

I would use it again for a similar trip.