Love that I can get hot water for tea immediately or even to cut down on the time it takes for water to boil in a pot: i just fill the pot, put it on the stove, and within 5 minutes it's boiling and ready for pasta or whatever you need to cook.
I also like the security feature which makes it more difficult for kids to use unless they've seen you do it a couple of times. Prevents scalding and gives an adult enough time to jump in and pre-empt anything. You can also control the temperature of the water. If you don't like it boiling hot, turn it down. Going on vacation and don't need to constantly heat the little tank? Turn it all the way down or off!