The SG is a $500+ pack system, it wasnt bad. But my kifaru with curved stays definitly fits my curve back better. Theres a reason kifaru offers diff options for this, it does help under a load.
I have an SG 5100 and MR crewcab. The crew cab is hands down more comfortable on my back when fully loaded. I find myself adjusting the fit of the SG over the course of a trip over and over, especially when changing load size dramatically. The MR is rigid enough to ride the same under any load I've had in it, with a couple far exceeding 100 pounds. I usually use the load lifters only when I have meat and otherwise leave them stashed in between the frame and bag. Currently, I use the crewcab for dayhunting and SG for overnights. Both are great packs, but you have to get the one that fits you best. My preference is MR in spite of the weight.
Thanks for all the input guys, I still can't make up my mind.
I started looking hard at the Kifaru Argali it would be a pretty light setup but I'm not sure about only having a top loading pack with no zippers. I love all the other features kifaru offers as in how modular their systems are. A part of me wants that but another part likes the simplicity of the SG packs.
Although simple they have a place for everything and I like how the pack bag, when separated from the frame to haul meet or whatever, attaches back to the load lifters for them to actually function again while separated.
Looking at the Argali, it don't look as if the lifters are attached to the bag when separated.