I haven’t done much of it. I have another Pilot Metropolitan with a medium nib which writes very smoothly. The stub nib isn’t as smooth, although my initial experiments have been on paper that’s not especially fountain pen friendly.

I also notice that I have to write more slowly with the stub nib or I get line widths that vary unexpectedly. Pilot calls it a calligraphy nib and I think it really is, rather than something you’d use for everyday notetaking. Perhaps those whose handwriting is more consistent have better results.

It’s too bad because I very much like how stub nibs let colored inks show. I’ve noticed that with narrow nibs, sometimes a colored ink doesn’t really “read” as colored when you look at it.

Many believe that Meta is using an embrace, extend, extinguish strategy here. See:

https://en.wikipedia.org/wiki/Embrace,_extend,_and_extinguish