Well, I look at it this way when the servo/control horn geometry is such. Either you rig for max mechanical advantage at full deflection, or it is there at the neutral point. I look at where my ailerons are going to be for the majority of the time, then arrange to suit.

Darcy - the way mine are arranged, there is perfect alignment at neutral. Only when the arms are at full deflection is there the side force you mentioned. I minimized this by arranging my setup as depicted, and only see this 'momentary' side force at full aileron deflection. Again, where you operate these the most should dictate how you set them up. Since I fly more IMAC stuff then all out 3D, mine typical are at neutral for the majority of the time. Hence you see my arrangement. The servo arm and control horn are in direct alignment and are at max mechanical advantage (for me) at neutral.

Ideally, the servo should be on its side to avoid all of this.

Spar