Bought this little sack with the help of the team in Manchester. Have used it for skiing, walking and scrambling; it is now my main day sack. It has survived many a big tumble on snow and ice and doesn't show a mark. The side pouches; front-slit and top pockets are perfect for storing the camera, Muesli bars, sun-glasses, solar block etc. My walking axe is a bit heavy for it, though it carries two walking poles easily.
Its a neat ergonomic fit on ones back and doesn't cause any sweating. Just my age does that!
I thought it may have been a bit small, my Winter sack is 30L, but it can carry my waterproof jacket, leggings, water bottle and lunch quite admirably. It weighs nothing empty too.
I have taken off the waste strap, for me it's not necesary and the chest strap is too high, so I don't use it, bear in mind I am fairly big 6'2". Neither are important as its only a light sack. I love the whistle in the buckle :-)
If I were doing more technical stuff than scrambling and skiing, then the chest strap may be limiting for me.
That said, I love this sac and reccomend it as a Spring / Summer day sac, for scrambling and for skiing.