I was comparing the shimano and campy designs for fsa 220 hubs,
http://www.fullspeedahead.com/downloads/copy_RD220S%20drawing.pdf
and
http://www.fullspeedahead.com/downloads/copy_RD220C%20drawing.pdf
It looks like the campy version does not have the 2nd nuts on them, which means it would require regular adjustment + faster wear due to the time the wheel is road out of adjustment. Then again this really only matters if you use the wheels for 1000's of km.
