I seldom eat dragon fruit because I find it a little bland. Sure, you would never get one that is sour.. (unlike some fruits) but you never get one that is sweet too. It just has this in-between kind of taste that I don't find particularly interesting.
But red dragon fruit has such a vibrant colour that it makes a really interesting drink. Blend some with ice and simple syrup and you'd get a really pretty drink.
It's a nice drink to serve when you have guests over.