James.
This subject is like the "cg no matter" topic, as many people there are will be as many answers as you'll get. IMO, it's a feel thing. IF you think it helps, it will. If you think without grips is best for you, then that's the way to go. Personally, I use them because the 'feel' and a slight swelling issue I have later in the season.
Cheaper, no grips. Ease of drilling, grips. Customer feelings ? I keep a couple balls in shop with and without grips so they can feel the difference and decide for themselves. I can not feel for them so IMO, it's 100% a customer desire. BTW, that's why they make Fords, Chevy, Dodge, Toyota etc, customer desires.
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az guy aka: R & L Bowlers Pro
rlbowlerspro@cox.net