I recently bought a [glow=red,2,300]Mocke [/glow] PFD, not just because Dawid is my hero, but also because:
-I like the design (quick drain, comfortable, etc)
-I wanted an onboard drinking system
The one thing I didn't like was the bite valve. It was noticably inferior to my Camelbak - the Camelbak bite value is awesome, its comfortable and you don't struggle at all to suck (sic).
You can buy the Camelbak bite value seperately, which I did, and then attached it to the Mocke PFD drinking system. The problem is the Camelbak value is too narrow for the Mocke PFD drinking system. But this is nothing a generous wrapping of plumbers tape won't solve. And there you go, a great PFD/drinking system with the best bite value on the market.