The Accu-gage EZ Air reminds me of the inflator attachment I often use:
You press the lever and it inflates, then when you let go of the lever a telescoping gauge pops out. It's not extremely accurate but I don't care to be extremely accurate.
However, I've frankensteined mine into an easier, more useful condition. That nozzle-ended pipe is a pretty decent way to put air in a tire for a few seconds, and is a necessary evil for inflating the inside tires on a dually, but what's better is having an end that locks on to the valve stem like the Accu-gage EZ Air has on one end. What's even better than that is having a quick-connect fitting and the easy ability to use either fitting, as well as a longer hose.
So, I clip it on to the valve stem and then I can stand up, operating the lever until I'm where I want to be. If I need to inflate a dually (I never do anymore), I can still attach the stiff nozzle instead. Once I'm done I check with a digital gauge.
I agree with BEEF, I don't find it important to be that perfectly accurate from one tire to the next.