Mid sole cleat positioning is fine as long as one makes a slight downward adjustment to his/her seat height because the effective leg extension is increased with the mid-sole cleat position. Without the adjustment knee problems can result. A number of pro riders have moved (pardon the pun) to mid sole cleats because it provides a few percentage points more power though sprinting capability is reduced. Standard clip-in bike shoes generally do not provide enough fore-aft adjustment to create a full mid-sole cleat position. One can buy cycling shoes that are specifically designed for a mid-sole cleat position though I'm not sure if these are available in the typical cycling shoes that a bike tourer selects.