The La Sportiva Otaki and Skwama are built on the same PD75 last compared to the Solutions PD80 meaning they are slightly less asymmetrical compared to the Solutions and hence slightly less agressive. The Solution uses a 1.1mm LaspoFlex P3 midsole with a 4mm Vibram XS Grip 2 half sole compared to the softer Skwama which uses a 0.8mm midsole with a split 4mm XS Grip 2 half sole and the stiffer Otaki which uses a 1.1mm midsole with a 4mm XS Edge 3/4 sole. I'd love to get my hands on a pair of either too post a descent review. I hopes this helps.