>>5533834Like any tool, there are pros and cons to using pens. Pro is that it forces you to draw quickly and not hyper-obsess over every minute detail of your drawing. Pen prevents you from drawing and erasing the same thing 100 times. On the flip-side, the inability to erase can put too much pressure on each of your strokes, and cause you to be too "safe" and not take any chances with your art. It also takes away the ability to do an under-drawing, which can shoot you in the foot as well.
Honestly, the best strat is to switch around between pen and pencil. Don't get too stuck on just using one or the other.