B17 for me is working great. My butt (right where my sit bones are positioned) are sore -but that is all. The leathers surface is showing signs of tiny creases in the places where my sit bones rest. That seems like it is perfect. Now I need warmer weather to come so my sweaty backside (sorry for the image) works that stubborn leather into shape. Keeping fingers crossed. You do have to earn these saddles though. Boy, howdy. They are not for those who are delicate. Got to have a thick ol' bike butt to work these bad boys out.