I have an all moving stab on my biplane and recently converted my monoplane to the same arrangement. My experience is that overall it is a lighter set up than a dual servo system or a single servo DEPS. I believe it is easier to build than a conventional stab (no elevators to cut and hinge) and and is easier to trim. No need to adjust the stab to remove elevator trim. I have the pivot point at 24% MAC and the servo torque is 7.5 kg-cm on the biplane and 8.8 kg cm on the monoplane. Difference is what servo would fit rather than a need for more torque. Seems to work fine. Certainly wouldn't claim any aerodynamic benefit, but easier to build and for trimming than the conventional stab IMHO. Bill