Gimp, I have used the Crazy Creeks for about 7 or 8 years now on my wood/cane seat Bell as well as the same style seats on my Penobscot.  Initially i was concerned about the attachment straps running parallel (long way) with the seat, but this turned out to be no big deal.  They work fine.  It may seem like a minor thing, but as DD mentioned, the value of a velcro strip included to fasten the back down to the seat when portaging should not be underestimated.  Crazy Creeks have these.