Key features that make it a great pack:
- Very stable ride -- even with a full load of 70 oz.
- Tons of room up front for food and etc. and space in the back for extras (ie. headlamp, emergency bivy, and other miscellaneos things). I carried enough calories in the pack for numerous 30+ mile sections.
- The shock cord is great to put a water bottle to fill-up out of streams/springs or for a rain jacket.
- The eating factor. I've had stomach issues in races that I've attributed to the constriction of my stomach area from the waist belt. I didn't have any stomach issues while running (albeit much slower than normal) with the pack.
I just thought I'd share my thoughts on a good piece of gear for those of you out there that might be in the market for a new pack or hydration system. (This is unsolicited and I have received no products other than the warrantied pack from Nathan.) There is a reason the majority of the folks you see running ultras are wearing this very pack! I just ordered myself the HPL#008 from TheAidStation.com for races.