I love the translucency and vibrancy of watercolors, but I don't like the way they bleed into each other at the boundaries. With the 3doodler, I can make a raised outline that I can then color in with watercolors.
I know there will be a lot of other stuff to do too. I decided to buy the project book, once I saw inside and saw the trace-your-own dinosaur skeleton project. :-)