I’ve used the Seek Outside Flight One Solid Spectra backpack on three trips now including the Uintas Highline Trail. The Highline was 104 miles over the course of 6 days, making it a great test for this pack. I don’t know my exact starting weight but I’m guessing it was around 30lbs with a few liters of water and a grapefruit. It felt heavy with 50% of the weight on my shoulders, so I ate the grapefruit right away. But as much as I messed around with the adjustments I couldn’t get the weight distribution right. It remained between 55/45 and 50/50 hips/shoulders for the remainder of the trip, even at the end when my pack weight was below 20lbs.