Word on the street is Hydrapak is busily working on redesigned bite valves for the reservoirs and some new designs to debut at Interbike.  In the meantime, for your entertainment (and to make you wish you had a job like these guys), here’s some of their, um, QC testing.
I’ve got one of these (not the pack, just the bladder) and the top sealing system is solid, but I am anxious to see an improved bite valve.  The coolest thing about them is you can disconnect the hose and it won’t leak…except that occasionally I’ve brought the bladder with me to the trail and forgotten the hose.
