Ya know, all that stuff is great ,but I just do up loads that are consistant in a particular gun and label them as such. It's worked for me for >45 years and I'd find it hard to believe that I'd be able to do any better with that gadget, Hell at my age I'm only going to shoot so damn good anyways!! No matter what latest gadget I get... old eyes ya know! Between that and these neck/ back spasms,, I got all I can do to get a decent "hold" anyways.
I have used cronies before and they are a usefull tool with out a doubt, but I can knock down what ever I shoot at with 1 shot anyways, and at just about any range to boot, so I'll just muddle along as I have for years with out one.
I must admit that IS one sweat unit though!! And for someone that does 1k matchs all the time it would probibley be an asset with out a doubt.