I've been running Saucony Kinvara for over a year now. My only complaint with them is that the cushioning only lasts about 250 miles. That makes it pretty expensive. The Cortana has the same 4mm heel-to-toe drop as the Kinvara, so I decided to test them out to see if they lasted longer. They have a more durable and slightly thicker sole so I hope that makes a difference. They cost 50% more than Kinvara, so if they don't last 50% longer, it's a bad investment. They are over an ounce heavier than the Kinvara and the outsole and heel are stiffer. I definitely feel the difference. On the other hand, when I run in Kinvara, my legs feel lighter and mentally it's good. I'll update this review when the Cortana cushioning wears out. ***UPDATE*** 12/20/13: It's been about a month and a half since I started running in them. The shoes themselves are ok, but the cushioning is no longer than the Kinvaras, but they cost 50% more and are heavier (that's why I'm leaving out one star). As I don't need the extra support they provide I only go back to Kinvara for all my runs.