As a student who prefers taking notes in pen, I really like these. I've previously tested other brands, and out of all of them, these are my favorite and fit my use case.
Pros: 1) Comfortable - Good grip, and it really just glides on the paper. No problems going lecture after lecture and going ham in my notebook. 2) Great colors - I primarily use black/blue depending on the class, and the other colors are vibrant for underlining/boxing/sketching diagrams 3) No bleed - At least for me, I use Kokyuo paper and some notebooks I get at an Asian stationary shop, both are a tad thicker than looseleaf.
Cons: 1) 0.5 vs 0.7. There's almost no difference between the 0.7 ad 0.5 versions of these pens. Uni-ball has a 0.5 that's actually thinner. 2) Purple is actually kinda useless. Don't get me wrong, the pen works just as well, it's just that I find the color unnecessary when I can get by with blue/black/red/green alone. But hey if you want a purple pen, go nuts.