[chiphead]

No direct experience with these, but I will comment in general about stepper-motor based gauges. They're great for production vehicles that need a cost effective electric solution for mass production. They are more complex than a mechanical bourdon tube pressure gauge. The accuracy is only as good as the analog to digital conversion circuitry and the resolution of the stepper motor itself.

If the stepper motor has a fine resolution, the movement of the needle will reproduce the smooth sweep of a mechanical gauge. However, if the stepper is cheap, you'll see the "notching" as the stepper moves between fixed steps several degrees of rotation apart. I find this distracting, as you can tell the gauge is hunting between steps to indicate the real measured value of pressure or temperature. So the only way to really know how they perform is to find videos online and observe how smoothly they respond.