Underperforming? I have used all those packs on one deployment or another. The only one that I really didn't like the the Molle, the frames kept snapping. I stil use my alice mountain ruc for some hunting situtations. Are any of those packs my first choice for packing out an elk. Probably...
Have you tried any bags on the frame yet. I have been looking at getting this frame and have also been trying to figure out what bag to use. I may try a large alice (mountain ruc) bag to start and see how it works.