The first time I realized my pack was light enough to unclasp the hip belt (not to mention breathing constrictor - err sternum strap) it was a complete shock. It was like discovering going without underwear - complete and unrestricted freedom - and a nice cool breeze up the backside.

The advantages of no hip belt continued.. I could move the pack around, put it on one shoulder, take it off for a quick photo op or viewpoint scramble, and not have to fiddle with countless straps every time I ate a granola bar or jumped over a log.

I often still use the hip belt when I have a full 7 day load of fuel and food, but usually just for an hour or so a day to give my shoulders a break. On shorter trips, I'll take a pack without one. I wish more packs had easily removable belts!