I used to write with a fountain pen a lot, they're really nice to write with. Most of my writing now is math though, and I've found that fountain pens aren't the best for that. I really like the Sakura Pigma Micron pens though. I think that they're made for artists, but I've found them really nice as a general pen. I specifically get the 05.
Which angle can you still use to reliably write with an 05 Sakura Pigma Micron? I had one and had to hold it almost upright, otherwise started to skip and scratch.
Copic Multiliner SP range didn't have this issue. Maybe I just had a defective/dried up Micron.
I've never had issues with writing. I've doodled with one occasionally, and have run into issues then. Checking it now, it seems fine at a 45d angle. It does require more pressure at smaller angles, but my normal writing pressure feels fine. I normally write at a 70d angle for reference.
I didn't know Copic made pens. I've heard really good things about their markers so I'll have to try one out.