Michael, I fully agree with you on the comfort comments. My struggle has been trying to outfit a 7 year old girl that only weighs 42 lbs herself. I started with what seemed reasonable, a REI Passage pack, which is an extremely well built pack, and plenty comfortable and I liked the idea that it can grow with her and my son. But with that, a NF Tigger, a Zlite small, 1L of water, a few clothing and personal items and the pack was up to 10-11 lbs, that was just too heavy for her. It was plenty comfortable, but after 1/2 mile she'd complain about the weight.
So this year my plan is to use the Jam2, still a plenty comfortable pack for light loads, the Tigger, a NeoAir and limit the personal stuff she brings and carry some of it and her water myself. I need to bust out the scale, but pretty sure I'll have her pack down to around 6 lbs, which will be a major improvement.