Sorry for the 'rant', I'm better now.
I threw both, the purple was longer, more snap, for me. The Blue hit harder, again for me, but the layouts were about 1/2 to 3/4 in difference pin/pap, I can't remember which.
As I said above, the Purple color and I just didn't 'click' and no matter what anyone says, if mentally one doesn't like a ball, the reaction will suffer, IMO.
I wouldn't mind picking up a Blue again, drill it a bit differently as IMO it was a stronger ball. Handle more oil, cover changed easier, but then maybe it was the color.
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az guy aka: R & L Bowlers Pro
rlbowlerspro@cox.net