I mostly use drills with no finger grips, but have some old stuff that I just didn't want to redrill. My track, pap, axil tilt all stay the same with or with out the grips. For example I have an old White Dot with grips and a newer one with out. Both balls are drilled the same, with all the static weights very close to each other. I used both of them during a practice session to do some PAP measurements and couldn't find a difference between the two.
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ROTO GRIP - King of Them All