I have a Thompson Peak. A slightly older design from what I hear, but basically the same. The 20# limit is definitely total weight. Optimum is 15# and below. With those weights, the pack is a dream to carry. Then again I am sure any pack under 15# will be great. Over 20# you can "feel it" and it is uncomfortable. YMMV If I have to go over 20#, I will switch to pack with a suspension, usually my MS Ghost.