I think the mars could seem weaker with less backend because it does handle more oil and it probably burning up more than the neptune..
I can toss my neptune on burnt and it will just roll smooth and arcing all the way to the pocket.. but some oil in the heads and mids with clean backend and my neptune will cover more boards than almost any ball out there..
I slow the spead down and use the neptune on the shark.. all backend.
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16-17 mph,350 rpm,PAP 5 1/2 x 3/8up, HighGame 300 x 3, High Series 782
Book Average 215 / 205,PBA Xperience ave180