I road a Rocket with dark side recently. The guy I know had just purchased the bike a few days before coming over to get a TuneECU download I have. We went out on a long test ride to see how the new tune was working. Me on his bike and him on mine. The new tune worked really well. He is very happy with it. However, I hated the handling of his dark side bike. He loved the handling of mine with Avon Cobra tires. 2 days later he installed a set of Avon Cobras. He loves them too.
The moral to the story is don't be cheap and ruin your riding experience. Spend the money for a good motorcycle tire.