But thats one of the issues, We are told that CDA's are a more economical way for the Jet to fly, giving track miles as you say and then intervening with speed control to help enable the compliance of a CDA is it really what crews like? or even variable on a/c type?
As you say sometimes it seems like they just want to stuff the nose down, and fly level for some time, yet ATC can be the ones judged afterwards with how compliant they have been, but as you say even MODE S not given us the ability to fly the a/c yet!