I'm sure that others may have had less messy experiences of chains than perhaps I have, but I guess having had the belt drive on my ZF9, I don't see any advantages of chain. I have really enjoyed the clean, hassle free experience the belt gives. Perhaps the ultimate breaking strain of a chain is higher (I don't know...) but does that matter in this context? In any case, a chain represents a negative in my book and dare I say, somewhat old fashioned.