Correct me if I'm wrong but it seems both use gps accelerometers, both map/anticipate the course, both control RPM of engine, both are adjustable as to how the rpm boost is given(pull type). The only difference I see is that zero off contols rpm via the ECM whereas z-box does it via the throttle body on fuel injected in engines.
(I can see that z-box on a carb engine would in fact have a lag time that could be appreciable.) But on fuel injected engines it seems throttle control would be just as instantaneous whether the input is from the throttle body or the Ecm. Thoughts???