I've got both the Arkel Bug and the Otrleib backpack harness. The Bug is superb; it's well designed, high quality, comfortable as a backpack, and very functional. I'd buy one again without question. The Ortleib harness is a total PITA, cludgy, and takes up far too much space in a pannier when not in use. The fact that you must remove and store it every time you mount your pannier to your rack makes it very inconvenient for daily use. It's also not nearly as comfortable as the Bug as a backpack.