Christopher,
I can carry a full Bearikade Expedition (which gets my pack to 30+ lbs) just fine. With that weight I notice that the shoulder straps loosen over time and I need to pull them down once in while.
Jim,
The shoulder straps don't slide on the horizontal bar. There is a piece on the bar (in the middle) that prevents the straps to slide towards the middle. My load lifters don't really do anything for me. Right next to each load lifters is the end of the vertical bar. So the bag is already close to the bag and you can barely pull it closer.
I use the pad holders. The pad protects my back from the bear can. The pad also keeps the frame covered, so no part of the frame touches me. When I tried the pack without the pad, I noticed the vertical bars, but had no issue with the horizontal bar digging into my neck.
Manfred