I would gladly trade the weight of a coil shock for the weight of a 40. In other words if you needed to save a pound, should have went with a Boxxer WC. Although the X-fusion rear air chock or the vivid air or the CC DB Air, all seem like viable choices these days.
OMG, that bike is so sick, very good setup, congratulations! The only thing i think that isn´t too good is the dhx air, it´s not very usual in bikes like this one!