I will remember this reference next time I am commissioned to draw some naked guys and their penises!
I respect the stylized renderings of this master. If an artist is working for his own enjoyment, it works. Portrait artists usually work for a customer, not for themselves, as this type of drawing would likely have been. In my pompous opinion, I doubt if this style would work well in most commissioned portraiture, however, since most customers (at least mine) do not want too much stylization and too much impressionism in line work and technique such as in the final post above.