I've taken the new Ruckaway Backpack out a few times now and I'm loving it. The weight sits nice and high and the straps are very comfortable. It's early days but the quality seems top notch, too.
The only thing I would change is the shape of the zipper. It turns towards the shoulder straps at the top of the backpack so it collapses under load. If you're holding the bag upright with one hand you can't undo it with the other - it's a two hand job. You can put it face down but then 15kg is restin...