My Exmark has the bands or little metal strips around each individual blade... but still just tosses dust and clippings out the front. Yesterday I was mowing the ditches and I was gold with dust afterwards. My black shoes were gold, blue jeans were gold, it was nuts. Its been super dry out here lately.
I always thought these bands around the blades were to increase the amount of suction each blade has so it can stand up the blades of grass while cutting them at the same time to get the best possible cut.