We had one in the office the other day. I'd really, really like one. lots of nice features (like the helmet holder – so simple, works brill), the magnetic retainer on the hose, the bladder has a clip to stop it sliding down to the bottom of the pack (easier to use than the camebak hook/loop version.
Material it's made from feels quite light duty, reminded me of spinnaker cloth in places, but does have reinforcement in wear areas. Overall it looks extremely well made as good if not better than camelbak.
I'd get one if I could justify replacing my current pack, which I can't, at least not to Mrs JB. 🙁