What's the rationale behind spraying the contents of a drinking bladder?
If you are using it for wild camping (i.e. no fixed water supply) I can see the benefits of a bladder under pressure for cooking etc.
Saves squeezing the bottle I suppose. Seems a bit like a solution to a problem which never existed though
Allows you to spray it without biting and sucking on the hose, useful if you out of breath. You can also share your water with others by spraying the water, so you don't have to share the tube with them. Spray it over your face or head when it's hot.
You can give your dog a drink, wash your hands, clean wounds and like ci_newman said, good for camping too, you can use the water by spraying it out to wash and cook.
You can also use the pressure system to fill up a other water pack, connect them together, pump it a few times and it slowly fill up the other bladder. Seen a video where the guy had two bladders and a filter system, he used the pressure system to filter the dirty water and fill up the bladder.
It's damn tough too, they did a video where they drove a vehicle over it when it was pressured and full.
That said! Expensive piece of kit when you can pick other bladders up really cheap, I got hit by customs too for £14 as well. The reviews are all good on it, the only negative I heard was the air pump falling off.
If anyone is interested:
http://www.aquamira.com/product/geigerrig-hydration-pack-engine-3-liter/