I love my Parker Sonnet and Watermans. But I love my rollerball - I see no reason to deal with the mess of a fountain pen, when I get the same ink-like quality with a rollerball.
The best part is that I can replace my Waterman rollerball refills with a significantly cheaper Signo (which gives me indelible, waterproof writing) or the Pentel Energel refills (which is as close to ink as you can possibly get).
http://www.lambdacurry.com/2017/05/cheaper-better-waterman-r...