In reply to bouldery bits:
The base of mine ripped after a year. Only a few millimetres, and I'm hoping repair tape both sides plus seam grip should hold, but still: disappointing. It has been dragged over soem rough rock in the Alps, but that's par for the course for a sack like this, and I would expect either a really strong base material or a double base, even at the cost of a few grams extra.
Also, as already mentioned: the lid pocket doesn't sit well when the sack is full, can seriously restrict head movement.
It's a decent enough sack, but I wouldn't buy another one.