While the design is certainly unique, if you're after a pack that can be stripped down for day hikes, cycling trips or just ultralight trips while still having the ability to clip on an extra 15L at a moments notice, the PK50 may just be perfect. The website doesnt mention that the aluminium frame is removable (so is the plastic reinforcement) so if you're looking to shed a little more weight its easily done. No complaints so far, great pack.
This review was written in the old system and had content requirements that are different than reviews written today.