well… under what circumstances do they have an actual advantage over a normal bladder?
I’ve never really had a problem getting water out of my tube which the Geiggerrig didn’t also suffer from. As to getting crap in your mouth, well anything that sprayed onto the mouth piece probably also sprayed into your mouth – if you really care a plastic end cap solves the problem better without the need for a silly, expensive system. It doesn’t make it any easier to drink whilst moving and makes it more likely that you’ll choke when you spray it down your throat.
The only reason we could see to buy one is to spray your mates when they faff at lunch stops.
I’m sure they have fans but between half a dozen of us* who tried them we all stopped using them even though they were free. We decided that we couldn’t sell them and looking at who’s still stocking them over here it seems we were right. I’ve already given mine away otherwise I would have sent you it.
*some of whom are the most gear-happy people I’ve ever known.