After using this at the busiest writing time of the year, study break, I can say that the Medium size has a very satisfying weight in the hand, which steadies it when drawing lines or diagrams. The build quality is excellent, some very fine machining went into this product. The bolt screw does loosen with normal use from the box, but I took a large flathead to it and gave it a good tighten and haven't had it loosen since. The cap and grip can loosen too, but again with some elbow grease I have made them so they don't slip during normal use. The Scmidt cartridge has a nice sharp point, and good ink flow, but ran out in about a week of writing.
pukekoIf you reach out to support@inventery.co I'd be happy to send over some ink refills, we're glad to hear you like the pen after testing it out in such an intensive writing setting.