Montane Grand Tour 55, think its 1.2 ish empty, can be less if you remove the spine (I dont), comfortably takes two weeks worth of gear/tent/doss bag etc, everything inside the bag ( and 5 or 6 days food),
I have a couple of smaller osprey bags that I love, but I just found the bigger ones need more strap padding, especially on long trips.
I also have a berghaus thing I bought in a mad moment, its mega comfy, but weighs a ton empty, it will never leave the shed again