Barney's packs, in my opinion, are for guides, MR and the Timberline are for guided hunters. DIY hunters may go either way. I have never guided a guy in Alaska who likes an external frame pack, even Barney's. They don't offer the flexibility of the latest models of internal frames. I haven't used the Timberline, but I am going on a Tur hunt in Azerbaijan this July and think, after what I am reading on Rokslide, I will try it.
At least 80% of the guides that I guide with in AK use a Barney's. I have the Pinnacle, which I believe is the largest (8300 I think). It is VERY durable, and VERY functional, and simple. The newer suspension system really helps the comfort and ability to pack large, heavy loads. The primary reason that everyone likes them, I think, is that they are easy to strap a moose quarter to. A BIG moose hind quarter will weigh over 165 lbs.(I have seen one weighed. It was hock to hip ball.) I have heard of guys weighing them at 190, and I wouldn't doubt it. Antlers also affix very easily. A lot of hunters and guides still use them, because that is what they know and it is what they have.
I personally loved the comfort of a MR 7500 pack, and found it to be far superior to a Barneys. I used it on Kodiak brown bear hunt last spring. It handled a 10'3" bear hide superbly, which weighed well over 100 pounds. However, I found the pack to be way too complicated. Too many pockets and zippers, that all led to compartments that were too small for my use and liking. I am like most guides and don't like gadgets and lots of "features." Like I said, that is why guides like Barneys; the simplicity.
So in my opinion, If you are a on a DIY caribou or moose hunt in AK, Barneys is the way to go. (And by the way I have used the lighter Nylon, not the heavier Cordura, and it is plenty durable: 6 seasons, and about 200 flights, and a fair number of animals haven't put a rip or hole in it yet,,,,, knock on wood....!)
I you are DYI hunting bear, sheep, goat, deer, or you are hunting with a guide for any animal, i would focus on MR or, it sounds like Kifaru as got the hot ticket....?
Best of luck!!
I have a knife and am willing to start cutting if something is that heavy. 
) But I would say Kifaru is king for comfort for me as I like how I can snug the hip belt all the way. If you have less than 30" waist and 100+ in a Barney's pack you might run out of room to cinch it any tighter. That said, you simply can't go wrong with a Barney's for hauling weight.
