I am in the process of building up a new 29er bike with full Sram XX and made a few premature decisions before researching all the facts about some compatibility issues. I built up some Crest 29er wheels with DT240 center lock hubs(15mm front, standard rear). Figured I would get the 6 bolt adapter to run the XX rotors. After finding out the standard 6 bolt adapter from DT Swiss is not compatible with XX, they have a new XX specific adapter I just ordered. The question is should I bite the bullet and buy XX center lock rotors and lock rings or stick with the new XX 6 bolt adapter and lock ring? Is there a measurable weight savings or any advantage of going with the center lock rotor or just using the adapter and standard 6 bolt rotor?