A diagonal zipper might function better, I don't really have zippered shoes.
I don't have sprints. I tried them on at the store, but again the lower vamp made my feet look fat (I'm kind of vain about that). I could also see the top strap irritating my foot since, but most people don't have that problem. The two straps on the back of the foot were different and would take some getting use to. I didn't feel like the sprints were as comfortable as my KSOs. Also, I felt that the w39 were a bit snug and the w40 too large.
I'm still considering sprints, but will probably wait for the bikilas, but only if the women have a better color choice than orange/pink.