Love this backpack! The side straps are very well designed to synch the bag down flat when it isn't very full so the weight stays close and streamlined to my body so it doesn't jiggle around when I move. The straps are highly adjustable and fit like a glove, the back is padded enough to protect my back from the discomfort of lumpy gear, but still allows a little air to circulate to minimize sweat. The belt is wide enough to be comfortable but not too bulky. I love that it is detachable.
I chose this backpack over many others because it can comfortably carry my very large yoga mat. Because the upper side straps are placed high on the pack, one can put a yoga mat vertically in the main cavity of the bag, synch down on the straps and carry it securely. You can also carry a yoga mat horizontally by slipping the outermost pocket over the mat and then attaching the top straps.
This is the second Camelbak brand backpack I've bought and I couldn't be more pleased.