Anyone have experience running carbon rings? I have been considering the aero/track DA 56 but like the lightness/kewlness factor of carbon. I am concerned there may be a durability issue as the maker recommends a single-ring set up but also says 2 is OK if you don’t slam the shifts. Is it worth it or should I stick with trusty DA? 
they will actually slow you down because you will worry the whole race about shifting too hard.