I'm sure a thumper supermoto would be the best fun on a twisty road, but it's still not the classic feet-back, head-down riding position that some of us feel comfortable with.
These hot 450 racers look the bollocks, but I'm a six footer and I just don't fit on them.
I'm not even sure what options are open to someone wanting to build a caff racer single with a modern lump, given all the FI and electronic jiggerypokery that you would need to find space for in a new frame.
Perhaps the only option is to do what the 450 racer kit companies do, they take the basic frame and motor from an MX thumper and add new subframes, yokes and forks, etc. But crikey, what would that cost?
GC