I wanted a sole giving padding under the ball of the foot. It turns out this sole isn't quite thick enough there for my needs, although for heel problems, I'd have thought they would be brilliant. I had to cut the metatarsal lump off, but that came away easily with a sharp knife and much improved the sole! They need quite a bit of room in the shoe (ie chunky trainer, boot or welly, and they do get very cold. I haven't found out yet whether my feet sweat using them (they're residing in my wellies, where they do provide a bit of extra comfort.