The appeal is the same whether it's fountain pen or rollerball or ballpoint.
Example, if I'm a Queen fan (which I am), and if I have enough pen-fund to pay whatever Montegrappa is selling the "A Night at the Opera" for (which I don't), then I will buy the fountain pen or the rollerball (or both) because primarily of the Queen connection. Whether it's the fountain pen or the roller-ball, is secondary preference.
I personally would (of course) prefer the fountain pen, but others may prefer the rollerball.
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