In reply to UKC/UKH Gear:
I've been using the older style Exos for a couple of years now and have been hugely impressed with it. It's worth bearing in mind that the long back 48 is actually 53 litres according to Osprey and mine swallowed backpacking kit and food for six days for the WHW without excessive swearing or stupid sacrifices. I used mine this weekend for a D of E exped and we packed lots of extra water for the kids on top of three days camping gumf and it was really comfy carrying over 17kg.
Kudos too to Osprey who repaired a small hole free of charge after I stupidly tore it catching it on a spike.
My only gripe with the new model is the loss of the hip belt pockets which are my new favourite thing.