I've used a Barney's, kifaru, SG and Exo. I couldn't keep the kifaru to stay on my hips but loved the bag layouts so much and the made in USA factor so I struggled with it for two years trying to make it work. Then I went to a Barneys and it is a great pack with beefy padding, seems indestructible and lots of space but even with the padding in the lumbar pad the metal would dig into my low back with heavy loads to the point where my legs went numb. I tried lots of different adjustments but once I went over 80 pounds it was just a matter of time before i could feel the metal digging in. For my body the exo has been perfect and carries heavy loads perfect. All 3 brands you mentioned are great and sadly you just need to try them out and see how they go.