Excellent question, and one I'm afraid I'm unable to answer, as I've never seen the lightweight ones in person. I would, however, suggest that the "blobbiness" of the last is in the eye of the beholder; it doesn't bother me at all, and in fact I prefer a more rounded toe to a pointy or squared one. Maybe I'm just weird. EDIT: The product page has an answer under Q&A, detailing thinner, lighter weight hides, a different shank, and a lighter sole. As a matter of fact, the uppers do look a bit thinner in the pictures... but I'm not sure that'd make me rush out to buy it. I've never had a problem with the weight of the regular shoes, regardless.