I agree. The biggest fault I see with most emergency packs is that they are based on bags that hang all the weight on the shoulders, which are simply the wrong place to on the body to carry much weight for any distance.

If the objective is only to contain assorted gear together in one handy place, than a bookbag style pack with shoulder straps only would be fine. But if the objective is to be able to carry more than 10-15 lbs for some appreciable distance, then a pack with either an internal or an external frame capable of shifting the load to a stout hip belt is called for.

My own pack is based on a Kelty MAP 3500. http://www.amronintl.com/kelty-map-3500-three-day-assault-pack.html