I went to Jackrabbit because I heard about their bio-mechanical feedback. They have a treadmill set up so after you try on a pair of sneakers, you get on the treadmill for about 45 seconds. They tape you running and then analyze your stride in those sneakers. So in addition to telling you that you over or under pronate, they are able to examine your form and tell you if the sneakers you are wearing actually improve your form. Prices are average, but the sales staff is great! I couldn't recommend them higher for the serious runner.