Interesting comments. Everyone has is entitled to their own opinion. For me, the "duffel bag on a frame has worked very well. But I might not have as much experience as some when it come to packing animals.
I do know since I have been using said system, with Kifaru Long Hunters, Granite Gear Flatbed, Seek Outside Evolution Hauler, ULA Epic (modified) I have packed 15 or more elk, (3 in four days, one year) 5 or maybe it's 6 sheep. A couple mulie bucks, all on public land.
I don't care for a lot of pockets. Finding your shi* in your pack is called organization and experience.
FYI, it works for me.
A few links to photos.
http://s597.photobucket.com/user/runsmtns/media/LongHunter.jpg.html?sort=3&o=395
