[elhigh]

I have a vac gauge - right next to the A-pillar as it happens, giving my geriatric old truck a grossly misplaced bit of boy racer vibe - that got wildly out of calibration shortly after installation. I re-timed it so it was correct and it went wildly out again. So my truck is evidently pulling 10" vacuum sitting still, with the engine off.

In terms of concrete numbers therefore it's useless, but still it gives instant feedback on minute changes of throttle position. So as far as that goes it gives a visual feedback on inputs that the pantsometer can't detect.