When I put WAT-AAH! in the fridge in cluster of milk, regular bottled water, and apple juice, Sebastian chose WAT-AAH!. The first time he chose WAT-AAH!, he said it was out of curiosity but he enjoyed it. I caught his enjoyment on video but for some reason I can't get some of my videos to upload onto my new computer. Just a little while later he chose WAT-AAH! again, over apple juice. When I asked why he chose WAT-AAH! over the apple juice, he said it was "because the bottle is cool and looks fun". I asked him about the lack of flavor and if he felt like his thirst was quenched and he replied with a simple "It's water mom. Water doesn't have flavor and I'm not thirsty right now, I just drank some water". That was a bit of a smart-alic answer but he was being truthful. It is in fact water, and after drinking about 1/3rd of the bottle of WAT-AHH! he wasn't thirst anymore.
There are currently four 'flavors' (unflavored) of WAT-AHH!; Brain, Body, Energy, and Bones. You can learn more about WAT-AHH! here.