S2R - think old school:
2 valve
dry clutch
oil cooled
S4R - latest and greatest:
4 valve
wet clutch
radiator (keep it filled with Bourbon for max cooling effieciency)
Personally I'm all over the S2R. It's just what the monster is supposed to be. That radiator looks silly sticking out beyond the limits of the bike (there I said it!). You want all that extra, get a superbike.
2 valve
dry clutch
oil cooled
S4R - latest and greatest:
4 valve
wet clutch
radiator (keep it filled with Bourbon for max cooling effieciency)
Personally I'm all over the S2R. It's just what the monster is supposed to be. That radiator looks silly sticking out beyond the limits of the bike (there I said it!). You want all that extra, get a superbike.