Will soon be mounting the Shimano Road Dura Ace SM-RT900 Ice-Tec Center Lock Disc Brake Rotor (160mm front & 140mm rear) to the SLR6 when the Newmen hubs go on the new wheelset. This upgrade from the Ultegra rotors will reduce the weight of the entire bike further by 38g. The cleaning of the rotor will be easier as the Dura Ace rotor 'Freeza' fins are painted black instead of aluminium silver.
Weight of the 160mm Dura Ace Rotor as seen below.