estasync, The CXP10 is one of my favorite rims, not too heavy and very strong. The RSX hub was usually available as a 7S, but I don't remember if it used a spacer behind the cassette or not, if not and you're running 8S+ there's a compatibility issue. You can measure the length of the free hub and compare with the Ultegra hub to determine if an issue exists, if not have all three wheels retensioned, ride the Ultegra/Open Pro wheelset and keep the CXP10 for a spare.

Brad