Sandy,
Did you mean 15-day hikes with it, or, 15 day-hikes with it? It sounds like you have it stuffed to the gills if it is pulling apart, so I am guessing two-week long trips. That is awesome but I doubt that that is what the Exos was made for. (And I thought I was pushing it…)
I am really torn about pocket material. Maybe my most loved pack ever was the Auspex from Mountainsmith and it had mesh pockets. But as I got into the stretch fabric pockets I found them hard to get anything into them when the pack was full. While I loved the Talons, I did not like the pockets that much. The Exos addressed my biggest complaint by routing the side compression strap inside. These are much more usable IMO.
The Argon’s pockets are horrible, but I expect most of our readers here have only seen one of those in a store…
My favorite pockets are on my Bora 95 mountaineering pack. They are pleated nylon with a drawstring. To drop the weight of the drawstring and cord lock the same idea could be done with elastic around the top.
Good luck with the search,

