Can a -400 bloke explain what this gee-whiz system does that a simple radar vector doesn't? I mean, can't a set of verbal instructions give you the same sort of direct-glide, continuous descent flight-path?
I would have thought the current inefficiencies are actually the convoluted flight-path/STAR/SID arrangements (particularly referring to SYD) that are politically imposed due to noise sensitivities. No whiz-bang CPDLC method will necessarily absolve us of following those requirements in the general sense.
I am genuinely trying to understand what this is all about - there seems a lack of info available within QF. Maybe I'm just driving the wrong bus though...