It's capable of incredible fine detail and I had to get my strong reading glasses out to give it a proper go, I also found that it modified the fineness of my line as I went along, much finer than I usually use.
Here's a snap of the first test
A close up
I'm not going to finish this particular drawing it was just a test, the drawing need to be refined a bit before it's inked but I might complete a version with this method later. As you can see with the close up the line is a little broken but that's probably a product of the surface more than the pen, I think on Bristol board it will come out a bit more regular.