I tried the pen techniques on Painter, and strangely, it looks super thick and heavy when I was doing it, but after I brought it into Photoshop it was extremely light! I don't understand. If the brushes don't perform accordingly, then it might be better to just stick with Photoshop.
edit: I cleaned up a few layers and resaved this in Painter itself, and that turned out a bit better, as seen above. Below is the original I was complaining about: