Just came back from a quick, uber hot and uber wet overnight hike with my new Zimmerbuilt pack and I have to say WOW. I packed a little heavy on purpose to get a feel for the pack, and for a bit of exercise. The XPac was waterproof enough to keep my stuff dry in a nasty pouring rain (I have not seam sealed it yet...), the belt and straps were amazing, I never felt the pack at all. Granted I only had about 17 pounds in it, but it felt soooooo good on my back, the belt was comfy and the pack carried like a dream.
Can't wait to give it a bigger workout.....