What is the status of the 735s? I had always heard their CASM was poor in comparison to other aircraft. They're only about 17 years old on average (I'm a Delta pilot, 40 is old, 20 is a average domestic jet ). But weren't the leases an issue because they came from a raw deal in Chapter 11 or something?

Whats the latest and greatest about the 737-500s? And if parked in the next few years... what replaces them? Regionals?