I had a kifaru fulcrum with a 26 inch duplex tactical frame, and currently have a SG sky talus 6900. The build quality of the kifaru was unreal, the nalgene holster was nice, but unfortunately it just didn't fit me. I found the belt to be floppy and not real supportive. The lumbar pad really worked over my piriformis muscle, even after switching to a smaller lumbar pad I couldn't get it to work. When I tried loading it up with a 60 lb sack of cement it hurt me. As much as I wanted the kifaru to be "the pack" for me, it just didn't work. The SG with the x-curve frame felt like it was made for my back (I have a lot of curve to my back), the belt didn't move and was very supportive. I've carried moose quarters on my SG and it's handled them very well, almost as good as my Barney's. Like others have said, their water bottle holder needs some work. Ideally I would say try both and see what works for you.