We will be taking our first cruise in June, and will be celebrating my son's 8th birthday while on board. Is it worth the $ to buy the decorations and have them decorate our room? Also - I have a long history of kidney stones, so tons of water is a must. What are your thoughts on buying the case of water from Disney ahead of time? I'm not sure we really want to fool with carrying a case on board and having to keep up with until we get to our room. If we bring reusable water bottles, how accessible is water on the ship (and more importantly, how does it taste)? Thanks!