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.