Apologies on the delay getting back here…
I purchased the Flyweight Rucksack but soon returned it. The reasons were two-fold: the shoulder straps were a bit uncomfortable and I didn’t like the lid design.
The first problem was with the pack was the straps. They’re just some neoprene with some nylon running down the edges. When loaded up with anything over 10 or so lbs I could really feel the edges of the straps digging into my shoulders. The padding wasn’t stiff enough to hold the straps flat so the edges would curl in towards each other to the point where there wasn’t really any padding touching my shoulders at all. Very uncomfortable even for just a few minutes
The second problem was the lid design. I wanted to use this pack with a shorty Ridgerest, which would have worked out fine if the lid was just a flap, but of course it isn’t. The lid is a shaped pocket sort of deal and would limit the amount of width one could have at the top of the pack. With the Ridgerest inserted it was pretty much impossible to close up the pack all the way.
I realize that the pack wasn’t designed to be used for backpacking but it looked good enough on paper to try it out. It didn’t work well. Fortunately, this gave me enough reason to but a 2009 ULA Conduit!