I've carried a Mont Blanc ball point pen for many years now, it's amazing how very careful l I can be about not leaving a $150 pen lying around to be lost or stolen.
At any rate, I bought a Mont Blanc fountain pen for $220 a few years ago and tried using it. It leaked ink all over my hands, so I took it back and got another. It wrote horribly, either leaving large skips or large ink blobs on the paper. So I took it back and got my money back.
I reverted to my ball point, and discovered a
company that makes gel ink cartridges for Mont Blanc pens. These work extremely well, and I have been very satisfied with them for some time now.