very true about the tires/ riding styles... I actually ran a Shinko Stealth (front) on mine for a while, and it stuck just fine, and lasted a good while. it's only downfall was extended highway runs would absolutely eat it up. i replaced it with another black, round tire and have also been having good luck with it.
a harder tire will, in general, stick well enough for a large majority of people, but you have to be concious of how hard you push it until it is warmed up all the way around. my pirellis were the hardest ones i've run, but once you get them warm, i have melted the front a little bit hangin it out there.
30,000 mile 919 survivor. No plans of stopping the abuse any time soon.