I'm fairly surprised by the abundance of negative reviews here. I've generally been loyal to either Delta or Airtran but since Delta is just so much more expensive and since they revamped their SkyMiles program, I've since ventured out and tried other airlines.
Sure US Air charges for food and the planes are smaller and there's less attention paid to customer service (I.e, no mandatory referring to customers by their name and other minor courtesies) but they have always been on time for me and have performed the services necessary to make my flight comfortable.
The planes are older than many of Delta's planes, but the pilots know how to fly them and I've never experienced a rough landing.
Flight Attendants have never been rude to me, always have been polite and thanked me for giving them my business.
It is annoying that I have to transfer every time through Charlotte or Philadelphia, but the airports are well maintained and the connection lay over times are reasonable.
I am satisfied enough with the airline for the price and assurance that I will arrive at my destination within an hour of prediction, and I will continue flying so long as they are cheaper.
Biscoff cookies are absolutely delicious, and their taste is absolutely enhanced at above 30,000 ft; however, they are not worth paying another 2~300$ for via Delta.