I have both - depends how I feel. I've also had a spoonful of coffee in the chocolate too - I find the chocolate quite bland so the coffe gave it a bit more flavour. I mix up the drink with a stick blender and find that it doesn't matter whether I add the coffee before or after. Hope you enjoy!
I use a stick blender - you can then whizz it up right in your jug and no blender to wash up!
I make mine both hot and cold - sometimes with filter coffee straight fro the pot, and other times with a spoon of instant...whatever strikes your fancy.
Don;t be limited by just Vanilla - the Chocloate and a few sweetners makes a lovely Mocha - actually, all of tha packs bar Strawberry are nice made up with coffee and if you are a coffee hound like I am, thats a good thing!