The Deuter ACT Lite 65+10 has been the most popular backpack for the 2008 season for good reason. This backpack has the best weight, to capacity, to price ratio of any pack of this size on the market today!
The X Frame suspension directs the weight towards your hips, increasing comfort and flexibility.
Features: Aircontact Lite Backsystem, hollow aluminum stays, top lid pocket with map pocket, compression straps, elastic cord attachment, stabiliser straps, ice axe loops, mesh side pockets, inner separator pocket, interior valuables pocket, and a separate bottom compartment with pocket
I've used this pack on extended weekend trips (3-4 days) and on week plus trips. This pack is comfortable even when loaded to maximum capacity (and perhaps beyond).
This pack will hold two Garcia bear canisters inside, one horizontal, one vertical, plus other gear.
On extended trips I use compression sacks, external pockets and a Deuter Speed Lite 10. This allows me to carry everything I need for longer trips, ie week-plus 8 trips, without re-supply.
Other comments: Harness is both fully adjustable and easy to adjust.