I didn't really mess around with mine as much as I should, but my first impression was that it wasn't that great. It the straps are too loose it wiggles a lot and its harder to walk then simply shouldering the boat. If you cinch the straps up tight, you break the cheap / weak plastic snap deals. If you have to hike under tree branches, another pain in the ass. If you have to take it off and put it back on to get your boat around obstacles, yet another pain in the ass.
All in all, I think its a good idea, but it has enough problems that I would not recommend buying one.