I got these as a foul-weather shoe to replace my ten year-old Sidis. They seemed to be solidly built, with a secure, easy-to-use ratchet. However, I can't speak to the rigidity of the Shimanos' sole, or any other matter relating to power transfer, etc., since these went right back into the box after I tried them on. The glossy, plastic-like outer shell on the 'lowers', surrounding the metatarsal area, seemed overly rigid and unyielding, once the straps were tightened even slightly. This resulted in a pretty uncomfortable fit--for me, anyway. It might be okay for those with narrower feet, although mine aren't that wide. I thought about trying a half-size increase, but they fit well otherwise. I thought that they might 'break-in' after a couple weeks and wondered if I should hang onto them. Then I realized that maybe it's not so much that this shoe is uncomfortable. It's just that Sidi shoes are SO ridiculously comfortable. The outers totally conform to one's feet. No fishing line-and-knob set-up. No need to cook them in the oven. They just fit. I've worn many brands through the years and nothing compares.