"Even in a 172, at cruise, you only need to apply some pressure to make the plane climb or descend, you hardly notice the yoke moment. I'm guessing that from the increase in speed alone, that effect is magnified in a jet ???"
If we are talking about "pressure", then no. Modern jets provide "Elevator Feel" which makes it really hard to move the control column fore/aft at high speeds. Unfortunately, PC joysticks don't have variable feel.
If we are talking about the movement of the control column in terms of angles, then, in most cases, if you move the control column at higher speeds to angle "x" you would get a much more abrupt pitch change than if you moved the control column to angle x at low speeds.
Rudder control is slightly different. As you fly faster, the movement of the rudder is restricted (Your rudder pedals become less effective at moving the rudder).
Ailerons are different again. On the bigger jets with inboard and outboard ailerons, the outboards are locked at high speed (and/or when the flaps are up). Spoiler movement may also be changed.
Byrna... Add a few extra rubber bands to your control column when flying at high speeds
Rgds.
NSEU