Haha, I like the DLC'd Boxxer more than the 40. Couldn't go wrong with the other parts though. X0 DH, Saint, works either way. Weight-wise, SRAM for sure. Shimano better f*cking start making carbon Saint cranks, and lighter Saint compo's.
carbon cranks are a joke for downhill the xo cranks blow up if they strike a rock too hard....but i think the v10 was kinda designed around sram and it overall fits the bike better