Having used an REI Lookout 40 for the past two years but would be interested in something slightly bigger, about 15% to 20% larger. Lookout 40 was advertised as 42L in size Large or around 2,550 cubic inch. However not sure what this number was referring to exactly. I was able to carry 3 full day of food in bear can BV450 vertically plus all my equipment but with the Stratospire 2 tent strapped outside below the bag itself. Problem was bag full to the bream which was somehow changing its optimal shape and deforming the back making it round instead of flat against my back.

Any suggestion?
ULA Circuit looks nice at 68L but apparently internal size is much less at just about 40L. Never seen one so cannot really assess its size with regards to the Lookout 40. Will it be larger than a Lookout40 and will I be able to put in horizontally a BV450? I hear the larger BV500 fits vertically.
I also like Zpacks as well especially the mesh on the back. Again not sure what to select as I am looking at about 15% to 20% larger than Lookout 40 but all OEM seem to be measuring volume differently.
Would like to keep under 3lb.

Minos