Gauge mode is more useful for tuning idle mixture on carburetors and for diagnostics. You could take some idle gauge readings on each cylinder and write them down. If your bike started running crappy later on you could compare new readings to the recorded ones, and determine which cylinder was giving you trouble. Generally speaking, the higher the vacuum, the better the cylinder is running. You might be able to diagnose a vacuum leak or a bad stick coil with it. Glad it's working well for you! Smooth GS'es are happy GS'es!