I'm not
100% sure, but as far as I know, mechanically they are identical.
Regarding the PC issue, I believe the 'III' will work the same with both, and that the 'V' hasn't been homologated for the SD yet, although it should work fine with it. I'm sure there was a thread regarding the SD and PCV, can't find it, argh!
edit:
http://www.superduke.net/forum/viewtopi ... hlight=pcv