As a TC person I'd better jump in then. Firstly at TC we do not have any technology apart fron the four or five times table (thanks CP) to work out your distance from touchdown.
We give it because we are required to, once on initial descent and again on handover to the No. 2 director (120.4)- the latter should be more accurate.
In defence of our foreign colleagues, the Heathrow pattern is well established and because of continuous descent approaches, you will usually get a distance of 20 - 25 miles from initial descent from min stack.
I assume other airports dont have to conform to the ridgid rules laid down for us.
Hope this helps.
