I currently have Shimano ultegra hydraulic road brakes, but have 6-bolt hubs and ice-tech rotors. The calipers for either appear to be the same as the XT calipers, so I assume one can use either. The road brakes seem to be paired with center-lock when they are bundled. Is there any significant advantage or disadvantage to center-lock? (I presume they are easier to take on and off, which, given the way I seem to blow through rotors, could be a reason to go with center-lock if I get a second set of wheels).