If you have RNAV procedures, you need tight speed control to keep the aeroplanes coming out at the other end at the right time. However. most airfields in practice use radar approach procedures rather than RNAV which cuts out the FMS system altogether. The best way for pilots to fly them are with autopilot engaged with Heading and Vertical speed mode in use- trying to handfly makes the procedure much harder to assess. This gives the tightest following of ATC instructions. At some stage an indication of miles to touchdown is useful, though it seems to be very much a guess by the controller and is only an indication of whether an extended downwind leg is in prospect. The pilots can then start making pretty good estimates of distance to go themselves and allow control of Vertical Speed. As long as level decceleration/flap extension legs are flown at idle power, they still count as 'continuous descent'. What has to be avoided is level flight with power on below transition level.
What is the basis of your interest? Is it professional? Some indication of your level of knowledge in your profile would be helpful.