FLCH
Generally on approach I will ask the director if he/she could tell me the track miles to run, this will give me an idea of how to plan my approach
They will usually (99%) of the time give you the track miles with descent to an altitude (from a FL).
It has been covered before, but when descending on QNH, the min RoD of 500fpm does not apply within the London TMA (therefore into LHR, LGW, STN). The prefered method to minimise noise levels is to achieve a continuous descent (CDA), ie without a level segment if at all possible. Obviously this is not always possible, but I know that at LHR it is measured for all operators. Not surprisingly home operators with the greatest local knowledge fare best with BA at 94% CDA followed closely by BMI, VS and EI (locals really!)
HTH
Edited to stress what is wanted is a Continuous Descent and not necessarily a Constant Rate.