Have one,
it's a barebone back: all you have is a large pouch with shoulder strap, belt, straps a thin piece of foam as back system.
Very light.
Moderatly comfortable, not too good for sweat management, shoulder straps are pretty thin, not a problem when carrying light, different story when carrying heavy on long distance.
Capacity is pretty important, but remember that general shape is quite tubular, so it is not (at least to me) as good as the figures say.
Top-Opening system is the lightest possible, but not too pratical: it is ok if you only unpack in the evening when preparing camp, but quite annoying if you have to reach it frequently (there are a large zipped pouch and small lateral nets)
Seems quite durable, Fabric is dynema: supposed to be bullet proof vest fabric (better than kevlar) rated to resist pretty good to abrasion. I hear it burns easily.
Review seems quite negative, but it is actually pretty good for weight and price. Volume for weight is pretty impressive. I carry it when I don't want to carry much, but want a large container ready in case I need one.
Still, for a dedicated hiking bag, I still prefer my Osprey Talon (although a bit heavier and smaller).
