I recently completed a 5-day trip in Yosemite with my new Arc Air 60L. It definitely carries better than my gen 1 Arc Blast (no load lifters, flat stays, 1st gen hip belt).
I spent some time walking around camp one afternoon carrying my buddy’s Arc Haul. I didn’t notice a huge difference in comfort between his Arc Haul and my Arc Air, maybe a slight edge to the Arc Air. Only time and use will tell on the durability of Arc Haul Gridstop fabric vs. Arc Air Robic fabric.
@Anthony – The Arc Air will comfortably carry more than 20 lbs. The Zpacks website says 35 lbs. for both the 50L and 60L. I never carried that much but I found the Arc Air comfortable at ~ 27 lbs. (with the drought many of the streams shown on the map were not running and being uncertain of what streams would be running I carried much more water than I normally would).
Bottom line – I’d be happy with either the Arc Air 60L or Arc Haul with a slight preference for the Air.