To answer your question about which the airline would choose, that would depend on a number of factors including the delivery schedule, the maint support, training, simulators, financing, whether or not they would accept trade-ins. Remember a while back Boeing sold someone some 777s as I remember and they took some relatively new A340s in on trade. Airbus said (for a while before retreating) Boeing has 'em, let Boeing support 'em. That didn't last long.

I flew the 737-200/300/400 and the 737 was never one of my favorites. I enjoyed the KC-135 (REAL Boeing 717) and had a great time in the 727. The 757/767 was like being in your living room. Flew the line with the 319/320/321 and really enjoyed the cockpit and once I figured out the logic, enjoyed flying the airplane. Far better ergonomics than the 737.. quieter cockpit, better seats and you could roast weenies in the winter and hang meat in the summer the air-cond was so good. Remember the 737 cockpit is the same frame as on the 707 and thus it is one noisy work place above 300kts. Not much area to stow stuff... like I said, good airplane but not one of my favorites.