I think they look extremely good, but I'd have to say if there were thin-soled morphs you'd probably double your potential market. Additional colors (especially scarlet), and/or a cloven-sole morph-effect at the front might lend it a certain appeal to others. A first attempt at a product (and frankly, this looks great) should really appeal to the largest possible group - the more folks become familiar first-hand with your work, the better received your subsequent works will be. Perhaps you could offer the morphs as a free premium to purchasers. Good luck with it, I know I'll be interested when I see it. Cheers!