I wonder if we're under the need a new light rifle syndrone? Gun writers praise'em and firearm manufactures love to sell'em and we listen.
My simple analogy: I've watched my wife carry-around a 10 Lb sack of potatoes in the grocery store for over an hour w/o any though of THAT HEAVY WEIGHT! Offered to carry it for her and she said its OK its not that heavy.
While we're convinced that a similar weight (MINUS a potatoe or 2) just "kills us" on a similar hike!