Spotlight, what are your thoughts on the 40d fabric on the Argon? I think 40d is a bit weak for a pack of that weight.
My impressions of Osprey has always been that they have rode fit and comfort as their selling points (with great success), and not necessarily design and technology. I do like the Exos series for an ultralight pack.
But hey, opinions are like you know whats, everyone has one.