Just my opinion, so not worth much, but I've been riding heavy cruisers for years now. Valkyries for the last 7 years, and now a rocket 3 roadster. I've tried everything. I did the darkside for a couple of years. My brief conclusion is this: The darkside tires give great traction and great mileage. That's about it. The darkside tires take the joy out of riding. Again, this is just my opinion. Motorcycle tires are performance tires. The manufacturer, the engineers that designed, tested and built the motorcycle determined what tire the bike would have to perform at its best. My personal experience agrees with their design decisions. Again. Just my opinion. I applaud companies like Michelin that have come up with new tire designs like the Michelin commander series that improve tire life and increase performance and are designed specifically for motorcycles.
My conclusion: If you're going to drop the money for a performance machine, put performance tires on it. Get the most out of your riding experience. Don't lose the joy of riding because of worry about the wear on your tires. Just like gasoline, you shouldn't stop enjoying your riding experience because it went up 10 cents/gallon.