I am running the Rotor 3D cranks and blades (28/40) with XX, it is awasome. Rotor cranks are run by the Crevelo test team last TDF and the Specialized MTB race team. Shifting on the front is instant up or down. Everything else is XX and no issues. I use a Shimano BB which works with the Rotor cranks. http://www.rotorbike.com/nueva/ingles/ingles.htm