I have had one of the German rucksacks with aluminum tube frame for several years. It's not a bad pack but I have found that for serious carrying chores, it can get a bit uncomfortable. During a Mt. Washington climb this last May, I was having a lot of discomfort with the frame ends causing rubbing. Also, some of these rucksacks have the problem of sagging when loading with more than 10-15 pounds of gear.
After Mt. Washington, I went looking for a well-designed modern pack and purchased a Northface large daypack. The difference is like night and day. The Northface is a big, big, improvement in all ways. Better shoulder straps with easy adjustment. Great hip-belt system. Good weight distribution and lots of tie-downs. Load can be cinched down for control. The new modern packs are a big improvement over the old stuff in many cases. Just my opinion.
Just purchased a new model Kelty pack for my teenage daughter. It is built very well. Also, the Jansport models seem to be pretty solid.