I'm also a fan of cheap fountain pens. I haven't tried the Platinum Preppy; my go-to has been the Pilot Metropolitan, of which I have both a fine nib and a stub italic nib. My problem has been that I tend to forget about them for a while, and they dry out and ruin the nib (probably fixable with a long soak). I guess it's just as well I don't collect expensive fountain pens!
(I did have a Pelikan M200, which is kind of the entry level for more expensive fountain pens. I broke the clip off carrying it in my pocket, and then a couple of weeks ago, my 6-year-old bent and crushed the italic nib by trying to draw with it. Another reason I shouldn't have expensive pens... at least I only paid about half of what the current going price seems to be.)
I also haven't been writing on paper very much for a while. When I was having more face-to-face meetings at work, I was using a notebook and pen for notes, and could count on using that time for practicing my handwriting. But even before COVID-19, my number of meetings dried up a bit, and now all my meetings are virtual, and I have org-mode available for note-taking.