Here is what I see from the portsmouth 2008 numbers. The SX w/spi is rated 71.3. No wings is a .995 hit, oversized non-standard main is .980 hit. There is no mention of a hit for a smaller than standard jib and no hit for the spi(mine is assymetric). The jib I can understand as there is no gain. The spin I run is quite an improvement over the SX spin so some penalty should apply but what?
I calculate it 71.3 x .980 x .995 = 69.52