I'll go against the grain here as well.
I have one and it works.
It works well on the 1968 Ludwig kit I've had since I was 12 years old. I'm now 44.
I use emperor batters and ambassador resonants.
My lugs are clean, this kit has been kept pretty well, but it is a gigging kit and my workhorse for all things.
I do also have a drum dial, and a tune bot.
For swapping out heads and emergency situations I find the torque key, in my experience has been a pretty good tool.
It gets me pretty dang close to the pitch I want without tapping drums, taking them off stands, flipping them over etc.
Yes there will be variables. And for recording a tune bot wins.
But for the price this is a pretty handy tool.
I find the settings of 4-6 as mentioned earlier to be about where I hang out as well.
It's a quick and cheap way to enter the ballpark of getting tuned.
Just my opinion.