Oh, interesting. I used to have all those doo-dads, an ACI and a digital level. Not knocking them, but I retired them all. I repeat, I'm not knocking the devices, I just decided they're not for me, because:
I found that I spent too much time dicking around with inputs that are almost immaterial even at 2-3000 yards.
At 3000 yards, changing the shot slope (shooting up/down) by 3 full degrees affects my elevation setting by just 0.1 MRAD - one click. I can guestimate to within 3 degrees, or put my phone atop the scope cap.
With my digital level from Long range arms, I found that I was always replacing the battery and again, dicking around trying to keep the rifle PERFECTLY level. Then I learned that a simple bubble level is capable of measuring to within a fraction of a degree - meaning that if your bubble is not perfectly centered, you're probably still within a quarter of a degree. With my Spuhr mount bubbles, if the bubble is touching the lines, it's exactly 0.5 degrees canted. You have to go outside the lines to be more than that. At 2000 yards, a 0.5 degree cant creates an error of about 0.15 MRAD in windage and half that in elevation. Not totally peanuts, and if I'm shooting that far, I'll try to level it as close a possible. But for everyday shooting, with the digital level, I found it was largely a distraction, and I should focus my attention on the wind....or the woodchuck that was popping up and down from the grass...
What are you guys' thoughts on these devices? Worth it or not?