I have an early NT Thumb Sixer and it weighs in at 11 1/2 lbs. When people see it hey say, oohh heavy - I couldn't cope with that. If I take out my Fodera which weighs not much more that a pound less - they say oohh Fodera want my kidney? I say its heavy they usually say that they wouldn't care. (perhaps more graphic expletives).
My point is that unless you have a bad back, are very modest in stature or build or happen to be 83 then whole weight thing is utter nonsense. Ooh I'm a healthy man in my mid 40's oooh 12 pounds!, couldn't possibly carry that across my manly shoulders on a comfortable strap for a whole hour! Skinny little girls carry 18lb toddlers around all day on one arm. Jeez.....man up guys............