Is the weight on the large pack really 6lb...
Is the weight on the large pack really 6lb 11oz.
Not quite, it's 6lbs 6oz. It's the internal backsheet and the heavier suspension that does it. As I recall, knanier laid out the differences between the Argon and the Aether pretty well, so unless you need the Argon's suspension system, that might be the way to go at 5lbs 2oz. The Aether series is also Osprey's best selling line. Might check out the Arcteryx Altra 65 and 75 if you want a great suspension system, and can handle the price tag.