If you like smooth, go with Medium nib, and if you like some feedback, go with Fine, as I said.
Writing on decent paper (not always the expensive one) with a decent medium nib pen is something everyone needs to try at least once.
[0]: https://www.amazon.com/Safari-Fountain-Charcoal-Medium-L17M/...
[1]: https://www.amazon.com/Pilot-Metropolitan-Collection-Fountai...