I've owned a couple of Koss folding sets in the past. The Porta Pros look a LOT like my older sets does, though the earpiece on the Porta Pros look a bit larger and perhaps more comfortable. I know the Porta Pros has its fans, but personally I never liked the folding mechanism design; I don't wear a crew cut or shaved head, and my old Koss sets--as good as they sounded from a SQ standpoint--ALWAYS managed to snag my hair.

Really hated that (OUCH).