What follows is in regards to comfort and ease of use. I don't know nor do I have access to dispatch rates and all that whatnot...
I've flown the 320 series, but never the 737. I will say, comparing the 320 series to the Boeing 757/767 series, the bus wins hands down in the comfort level. There really is no comparison in the ergonomics of the Airbus. You can debate til the end of time about the pilot/aircraft interface, FBW and all that, but the bus is flat out more comfortable, and not having a dam&* yoke in the way is a nice touch. Roomy cockpit, relatively comfortable seats, plenty of room to stretch out.. it's a nice ride.
To be fair, I'm comparing a brand new off the assembly line A319 to a 25yr old design 757. The bus SHOULD be better, or someone isn't doing their job.
Boeing screwed up by not updating the 737 more... they could have made the NGs a much nicer ride for the guys up front, but some airline decided it's still the pilot's responsibility to close the fields on the generators and whatever archaic crap y'all do on that overhead panel.
In the back, the bus is more comfortable and quieter (to my ears) than the 737-800 series. This is coming from a couple of years of riding DAL up to LGA from DCA and using USAir for the ride home. The bus lands softer, too, but that might be the large number of navy boys at Delta..
