Installed a Yoshimura RS2 exhaust, ditched the air snorkel, and jetted the stock carb today. Installed a #40 pilot jet and #117.5 main jet.
This thing feels like a different bike. Before we simply short shifted as it didn't really pull. Now it really pulls at the top of the RPM range (and sounds great doing it!).
Yoshimura sent me a dyno sheet showing impressive gains, especially beyond 7000 rpms. My seat of the pants dyno confirms it. Next purchase will be a No-Toil air filter.