Ink pen alternates Uni-Ball and Derwent Graphik

This might really be two items but since they are both about types of pens I decided to combine them.

  1. I’ve seen Uni-Ball Vision (rollerball style) pens used instead of dip pens and the results looked pretty good. They certainly seem less messy than nib pens. Has anyone used these and have an opinion on the?
  2. Derwent Graphite Pens, Graphik Line Painter Colored Pens. My local online supplier actually has a good deal on these so I was wondering if anyone has experience with them? I’m not really sure how to classify them or how to use them but they look somewhat interesting.