if your in the market for a bad pack you can't go wrong with the new(ish) arc'teryx pack Arrakis 65, I havn't brought 1 but a friend. I forget how much but i know he paid a lot for it. When you first look at the pack you think wow thats nice, then he realised how difficult it was to pack, then he realised it squeaked.. still at least I got a laugh. great care in pack contruction though and great customer service.
Some of the Arc'teryx packs look tasty but even looking at them makes my wallet scream in pain..... Osprey 70 is ~£150, Arc'teryx Altra 65 is ~£300!
Is are the extras worth going for over the ~£50 saving if you get the older Osprey model? Especially if there is 400g of weight in it! I'm quite lightly built (despite being 6'4") so i try and keep the weight down where i can.