Aviation Leak, I mean Week, had an interesting article on how the A320's all-digital flight-control system has been somewhat of a headache for JetBlue in terms of maintenance downtime. Nothing serious or flight-safety affecting, but they do have to "reboot" the aircraft a good deal on the ground.

As for financing, Airbus cut JetBlue a huge discount to land the deal, as they had been losing out to Boeing with Southwest, Ryanair, and others.

Boeing's biggest advantage with the Next Generation 737s is that many "budget" airlines start(ed) with older 737-200 through 737-500 planes in their fleets. When they're ready to "buy new", they already know the 737 inside and out, which gives Boeing a major advantage (Boeing still deals just as hard on price, but price alone is not what wins 737 orders).

JetBlue was an Airbus customer from "Day One", so they had no "investment" in the 737 and therefore, price alone was the major determining factor in their fleet choice.