First, this bag is PERFECT in terms of what it can hold. It's exactly what I've been looking for in a camera backpack. I love that part of it. However, it is extremely uncomfortable for me. No matter how I adjust them, the straps cut into my armpits. If I make them looser, the pack bounces off my behind and quickly leads to an aching back. If I try and cinch them up, the straps dig in to my flesh and the pack rides way high on my back. There is no comfortable middle ground. I am not a large person - 5 foot 9 and 170 lbs - your basic medium t-shirt shape. I must say I'm really disappointed in the comfort of this bag.
For me, the padded upper straps are too short for the size of the bag. They need to be at least a third longer. Comparing to other non-camera backpacks that _are_ comfortable for me (e.g. North Face Surge), the straps on the Mini Trekker are substantially shorter. The location of the strap attachment points at the bottom are probably also contributing to my discomfort.
I really like the build quality of Lowepro bags, but this is one I'm not going to keep.