I have done a boatload of research on backpacks. It is enough to make a person crazy. I want something lightweight (of course), but the more I read, the more it seems that weight isn't everything in a good pack. The pack needs to be engineered in such a way that the weight (~30lbs) is delivered to the hips without straining the shoulders too heavily. Since no 2 people are identical, it can be quite a challenge (read toss-of-the-dice) to select that pack that will work the best for the individual. Quite frankly, I don't know how anyone makes the best choice.