AzTR,
I have Williams 58 carbon tubs and have had no issues racing on them for 2 seasons. My son also has a
pr and even uses them for cross racing. My son also purchased a set of Williams 38 Klinin's from Keith Williams. He did has some issue with the freehub which was replaced my Williams. My 38's are Psimets and have Kinlin rims and the Power Tap. Can't help with 38 carbons.