Why They're CoolThe treadsmade of softer tacky carbon and resembling mini-cleatsbehave like knobbies, plowing through gunk instead of caking up, while a perimeter ring of harder carbon-rubber lugs gives good grip. » After a stretch of riverbed mudflats, I sprinted up an embankment, yet didn't end up falling on my face. » The Pearl Izumis are attractive in a utilitarian waylike a vintage Jeep CJ. The overlay-free design, and a tongue base sewn into the upper on the outside of the shoe, rather than inside, reduce abrasion on really long runs.Hmmm . . .I heard more slap than I did in lesser models, meaning these require some breaking in. Either that, or I run like a duck. Quack?