Former Platinum and Club Member on America West. Once the US Air Merger happened I can tell you that customer service went down hill

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I stopped flying US Air last January after a horrible flight experience from MCO to PHX. I live in PHX, and fly Southwest almost exclusively, now. I dont get seat assignments, but their employees seem like they're happy to work there and my on-time arrival experience has improved dramatically

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US Air's frequent flyer program stinks. The average freq flyer ticket from PHX to MCO takes 50,000 miles (It used to be 20,000, then 25,000). You can occasionaly get by with 37,500, but that's very rare. To put that into perspective, you'll need about 11 cross country round trips to get 1 free ticket. When you compare that to Southwest where you can get a free ticket for every 8 round trips regardless of the mileage and add that to the fact that in most cases SW is much cheaper, the decision for me was clear.
Others might have a different perspective, but for me, they're not up to par. It is difficult to do from PHX, but I do anything I can to avoid flying them.
I am now 11 months US Air Free .