I think some of you are still missing the point.
Mass balance is solely for the purpose of moving the resonant frequency of the control surface out of the speed range to avoid flutter. It has no significant effect on control forces.
Aerodynamic balance is for the purpose of shaping the stick force gradient and has little effect on the resonant frequency.
“Spades ideally counteract input pressures to the point that the aileron will stay where it's put; this reduces the "feel" to zero, which some pilots like and some don't, …”
Such an airplane can’t be certified per FAR 23, which says in part “The stick force must vary with speed so that any substantial speed change results in a stick force clearly perceptible to the pilot”. Although experimental aircraft don’t have to comply with FAR 23, an airplane with such a neutral balanced surface would be quite dangerous to fly.