Grew up in MN drinking tap water - think the water at Disney is pretty bad. It is clearly much worse at MK, I can even taste the difference when I get a soda at the QS restaurants - they just can't seem to filter out enough of the sulfer. At the other parks it just doesn't seem as bad. I can drink that water from the QS as long as its really cold. But honestly, I usually end up buying the Dasani even though it's ridiculous to spend $3 on water (or $12 for our family of 4). But at least then I know everyone will finish it and stay properly hydrated, which in the FL heat is the most important thing.