To me the real worth in Redox (and actually all test gear values) is being able to tell whether something is amiss, or about to be so.
Knowing what your systems usual ORP signature is during an interval, seeing a sharp (@50 mV) or steady (5-10 mV) change per day should lead you to further investigation (and reaction). IS there "something" dead/decomposing in the system? Did a "little helper" pour in a whole packet of food? Is your protein skimmer on the skids?