Gershon and I are on the opposite sides of the new-gear thing by preference, not for any objective differences. For me, trying out a variety of different stuff has almost become a sub-hobby; I'm luck that my stage in life (no kids, mortgages, or vices other than gear) allows me to indulge this. I've also been lucky in that my "rejects" end up on the trail anyhow, in someone else's pack.

However, there's nothing wrong with his approach - it was my approach, too, back when the kids were at home (with college tuition staring at us), and home was still mostly owned by the bank. It worked, and worked well.

My advice was given under the assumption that the decision to buy a new pack had already been made, and you were just narrowing the list. If you already have a pack in the 40 - 50 liter range, try a couple of trips with it, and make sure you enjoy the overnight part before you invest in a lot of gear.