433- Not to be forgotten is the fact that it takes time for a descent to reach VSI demanded levels. Setting cleared altitude, then VS and punching the 'do it' button, the thrust levers pause, then slowly start retracting. That can take 10-15 seconds or so. Falling speed is detected, so the autopilot starts gently nosing down so that people in the cabin don't even feel it. Then the rate of descent very gradually increases. I think in the heat of European control, you may not allow for such finesse- much of the first minute can be taken up with getting the descent up to the rate requested. Allow for the descent to stabilise and see that it is still not quite the demanded level and time to think what to do........ Just don't expect high speed jets with pax to respond rapidly.