I bought all the brushes and the color mixer but I refuse to give this company any more money. The number one feature requested is the ability to use your own images in the app. All they say is "we're considering it."
That tip looks rather large for something with internal electronics. There are styli out now (Adonit Jot Script) that use those electronics to emit a capacitive signal which allows for a much smaller tip. Since they don't yet have pressure sensitivity, I'm still waiting on projects Mighty and Napoleon from Adobe.