I use mine occasionally. I still haven't tried the tea concentrate but this bump reminded me.
I just bought some Pom pommegranate juice (has a lot of nutritional benefits, apparently) this wknd and added it to seltzer I made in my Soda Stream. Pretty good.
I keep saying i'm going to concoct some kind of fizzy coffee drink but I haven't so far.
I use regular tap water that has been chilled in the fridge. (In our house, bottled water is for company LOL)