Q Feel Clarification
To clarify t.o.'s post...
Q feel is an artifical feel system which is made to be proportional (or at least dependent upon) dynamic (or more properly kinetic) pressure, typically denoted as 'q', hence q-feel.
Therefore one must rely on something more sophisticated than springs - the traditional way would have used some form of bellows arrangement, providing a direct 'q' input from a pitot-static source. The more modern way might be to use actuation of some form either as a direct force system or to mechanise a lever system to provide varying mechanical advantage over a fixed spring.
The advantage of q-feel is that it restores the control forces to a proportionality with the airspeed, in a similar manner to a manual system, and therefore the force feedback to the pilot is roughly proportional to the effect of the controls.
(1 deg of elevator at 300kts will create roughly 9 times the pitching moment as 1 degree at 100 kts; the pilot should therefore have to pull 9 times harder to obtain that 1 degree of elevator, in order for the relationship between pilot force and aircraft response to be similar at both speeds. q-feel provides the means to generate that force multiple.)
Note that a clever mechanical system designer can do away with q-feel and provide similar feel harmony to the pilot by means of carefully chosen system non-linearity using only "springs" and levers. But there is inevitably more of a design compromise involved; you get what you pay for.