I have a Kelty External pack but when I hit the AT for a thru-hike I would like to pair down the weight. This Kelty weighs about 8 lbs., empty. I have read lots of threads and comments about packs. It seems to me that the ideal would be a ruck sack. And use one's pad to line it. This is simple, inexpensive(?), lighter (no frame). That said, would all of you please comment on brands and types, etc. BTW, the Kelty I have is at about 5500 ci. I never fill it up and am very disciplined on what I take. Thanks one and all. Also, in your opinion feel that a rucksack would be a drastic mistake, let me know that also-and why. What would the acceptable weight of a rucksack, empty? etc., etc. -SunnyWalker