The first thing I anticipated working with this medium was that all of my strokes are the same size and I would be limited by the thin line quality. The pen definitely takes some warming up to. Getting a consistent flow of material is vital or else you wind up with a stringy mess.
While using the pen, I developed the mindset as if I were working with a hot glue gun. The same basic principle is applied with both tools, and in my experience the 3D pen suffers from the same problems you would encounter with a hot glue gun. While I was working with it, the pen seemed to have a tough time maintaining a hot enough temperature to melt the plastic. This problem led to inconsistency in line weight and the stringy mess I mentioned earlier. This problem in particular prevented me from working continuously, as the pen would need to reheat every other minute. I think this problem may stem from the speed in which I work. I’ve since noticed that the pen encourages you to work as slowly as possible and, I may have been working faster than the pen could keep up.
These gripes aside, when the pen was cooperating I found it to be comfortable and precise. I have already ordered the extra nozzle set for the pen and more plastic to work with. It was as rough start but I’m hoping that with more practice I can tame the 3Doodler.