We advised centre that we were happy to slow to let them go number 1,
Hate to point out the BIG PICTURE, Dubya, but you most probably weren't number 1 to begin with! there was probably a bunch of aircraft in front and behind and as you were
dragging the chain at an econ speed, Maestro required some whip crackin'. It ain't as easy as swapping positions. (Unless you're going into a sleepy hollow like Adelaide). Then of course you were already below the other aircraft. Plus computers make mistakes (count yourself lucky you've nothing to do with ALOFT and the 6am arrivals to SYD).
If the speed reduction was delayed until 8,500' ...
From an ATC perspective, agreed. Perhaps 9000ft to make it match the crossing requirements. But you have to push your airline's management to push the change to Airservices.
Agree with the comments re London ATC. In excess of 95% of our approaches are logged as within a constant descent profile criteria established by NATS. Approach always give accurate track miles to run when leaving the hold which allows descending onto the glide without levelling off, creating noise and burning excess fuel.
Doesn't the fact that you've been in a holding stack defeat the purpose of a constant descent arrival? Shouldn't CDA be from cruise/TD? All the same, interesting to hear that London TMA can get something like this up.