Honestly I didn’t really notice it being that different when I mess with the hose valve, but maybe I just don’t pay that close attention. Mine seems to spray pretty consistently regardless of how much I open it up. It works fine for me on the driveway and patio.
I think with most of these spray-on scratch things you’re always going to see them again in certain light. I just look at it as a quick way to make the car look cleaner between washes rather than a permanent fix.
A week’s battery is honestly tempting. I wouldn’t trust any noninvasive glucose claim without FDA clearance, so I prefer sticking to a proper meter for anything important. Would love to see an actual side-by-side comparison from someone though.