We tried out the backpack for Maddy today. We got a little carried away with the hike (this has happened before), usually Heidi keeps me in check, but she'd had a redbull ;)
So on we went to the top of the ridge at 3000ft, Maddy seemed peretty happy with the pack. 
It ended up being a 7 1/2 mile hike. Certainly felt like more ;) And even though the camp ground is full we rarely see more than 3 or 5 people out hiking the trails, Which kinda great for us but a sad reflection at the same time.