Beautiful brushes. I know what you mean about feeling the pen in your hand. I recently tried to draw some maps directly in Photoshop.It turned out to be quite challenging and I still prefer to work with the traditional medium. I just have to practice more I suppose to get the "feel of the tablet".^^
Using brushes in Photoshop the way you do seems very tedious and difficult to me. How do you avoid the overlapping? Do you erase the unwanted bits keeping the brushes on separate layers? Your maps look entirely hand-drawn, if I did not know it, I would not suspect the use of brushes. I truly admire your work and techniques.