No problem running at high speeds on the slab. We did it 2-up and a full load for hours. Your RPMs will be around 5,000 compared to a v-twin at under 3,000 but no real vibration, more like a buzz. You might miss the weight stability and low-end torque of a v-twin but you'll be ok. A 6th gear would be nice but rumor has it the new Mystery Cruiser will have that.
