I took the plunge and bought some of these. I was informed that brackets needed to be fitted to the pillion peg mounts on the subframe, which would obviously be a big job but when the panniers arrived, I discovered that they do in fact simply clamp to the pillion peg support arms which makes them a quick and easy fit. Because I have already fitted the Sato race hooks, it's a very quick job to remove the lot! Very impressed with the quality and design. They are incredibly stable on the bike and all that remains on the bike when you remove the bags and support arms, are the black receiver units. They were £245 but have been reduced to £218 on Motech's website now. If you are looking for some top of the range panniers, I can certainly recommend them.
Number plate fixed ! Went out for a spirited test ride with the panniers on. They were rock solid. Very impressed.