Just ordered one, did I make a mistake or is it as good as they say?
I have had mine for just over 2yrs, still going strong, I commute to work on my bike, so use it everyday, just so comfortable, don't even notice it on, even when its full and I've done 500ks + in one ride. It does not move, regardless of how fast you are going, just sits in place, the only time you notice it is when you stop to take it off. The only thing its needs is a waterproof cover to slip over it, as its weather proof but not fully waterproof. Always get comments like "are you going skydiving" because of the way it clamps together but I'm laughing at them because its the best motorcycling backpack around!!! haha
You have not made a mistake.
I also have a jacket with hump and it makes no difference.