There is a difference, I throw all 16 except for one ball at 15 7oz and one at 14 15oz. I don't notice the one at 15 but the one just under 15 is enough that I notice and I do get a little more speed on the ball. It is a good ball to switch to if I'm getting tired at a long tournament. I don't see any difference in RPM with the different weight, just a little speed.
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Always be sincere, even when you don't mean it
The Cell Pimp