I filled my new TWSBI Go last week when it arrived. I already used an entire fill of the Lamy Vibrant Pink. I did some more doodling with it just to get a feel for the lines and shading. The thickness of the lines is very close to what I was wanting.
I can draw with this Pen and ink combination for very long periods of time without any drying of the nib. This is great since the paper is not the greatest for fountain pens. The paper here is a small journal 8"x 5" size paper. It is made by Pacific Giftware is what I can see on the sticker inside. I bought the journal because it is wire bound and has a really pretty cover.
The TWSBI Go with Extra  fine nib just draws and draws on this paper with no feathering. I also noticed there is no pilling of the paper in my nib.
The pen writes fast and keeps a uniform flow of the ink. When the pen is just filled, I can slowly draw and get richer darker lines. If I really want finer lines I can reverse the pen nib. I also noticed as the pen runs low on ink the lines seem to get finer.
A really big plus for me is after using this pen all week, I didn't get on drop of ink on my fingers. No leaks or surprises.
I am so excited after seeing reviews on youtube about the different pens available. I can get an idea of what the lines will look like. I am getting a Moonman M2 next. I am planning which ink I will use in this new pen. It is a demonstrator pen. So it needs to be pretty like Apache Sunset or a green color.
I think I should title this piece "Everything is connected".