Song uses Delta planes, but they are redecorated with really cool and hip colors in the cabins. The flight attendants make an extra effort to be funny, which my kids enjoyed. They also enjoyed the fact that GameBoys are passed out to the kids on the flight. The drinks are still free, but the snacks/food must be paid for. They give you a menu with several chioces, and my kids liked that, too. We always book seats in the front part of the plane, and we get extra attentuion from the flight attendants, where they seem to hang out.
I have a pre-teen son and teenage son, and they think Song is the coolest plane they have ever been on.
We never had any problems with Song at all.