I've used nylon soled Mavic shoe for the last two years of CX and have had great luck with them. I find them comfortable, and especially easy to run in. That said, these shoes were cheap and are falling apart, so I was going to invest in something new. I use carbon soled shoes for my mtb and road bike and love the efficiency that carbon can provide. I guess I'm just nervous about running in varying terrain with ultra-stiff shoes. What do most of you think about carbon soles for CX? Thanks in advance!