"Ultra light" and similar terms are deceptive unless you're doing a true FSO start-of-hike weight, with water (1 liter when water supply is no issue), but for me, without food, which varies depending on days planned. I've always considered 15# FSO to be ultra light, since I always carry 2# of water and 20# to be light. It also depends on the season/climate/altitude since clothing needs vary.

The Weasel