Hey, I'm riding a supersport and I'm Dutch. Well half anyways.
I stand at about 6'1'' and don't have any problems. A Yamaha rider huh? Well I wont hold it against you.
My cousin rides an R1. Stunning looking bike actually. I have ridden it a few times. Plenty of power!
As for twisty roads, yes we have them. I'm in California with the Sierra Nevada mountains only 40 minutes away. Then the coastal mountain range is the other direction with some nice roads as well. With that said, where I live it is pretty flat. Maybe a bit like the Netherlands?