Earlier quoted context omitted.
Adding a bit of water brings out flavors you don't experience neat. It's a personal preference. http://youtu.be/ajqd62fE73E?t=6m23s
I've heard this, but I don't really buy it. The whisky is already diluted at bottling time, unless it's "cask strength".
But still, you can certainly taste the difference and decide which you like best.