Good question Stingo!
I was sailing open class this weekend on my stock H-20 and got killed by the PN#. However, the course felt short and the wind was good, the ARC 17 may have not have been depowering as much as the H-20. The H-17'2 were also very fast upwind this weekend, many rounding A mark before the Arc, but then got clobbered down wind.