Tri shoes from what I've seen are built to be easy to get in and out of quickly so you can be efficient in your transitions. As far as build goes I don't really know what the differences are, or what the set back to using them for road riding would be. I figure it's just another one of those things that appeals to people who want the utmost performance. I'd say if you're just doing tris casually maybe look for the shoe that fits the best and fits your budget rather than a tri specific shoe.