To give you an idea, with my very limited experience:
It takes roughly 3 miles to loose 1000' and 10 miles to go from cruise speed to a sensible arrival speed. They are realy slippery and without introducing extra drag (ie dunlops or speedbrake, flaps as a slow down method is a no no due to operating close to the flap limits) they will do both slowly.
Descents are ideal with the thrust levers at flight idle and the pitch controlling the speed. If you need to slow down as well as go down then the pitch attitude must be increased (more nose up) this in turn reduces the descent rate.
Nick
ps its all about energy management