Power for vertical speed, Elevator for speed yes, but when you think about it, elevator is going to control vertical speed as an effect of changing the speed, so I kinda smooth both methods out together! Just means fewer irrational power changes, and pitch movements.
E.g. Too high on approach, reduce power slightly, and lower nose slightly. It's alot smoother than Killing a load of power, and waiting for the speed to decrease, and thus vertical speed decrease, or vice versa with the elevator.
Cheers