Gregor in Graphite

With this portrait sketch of Gregor, I did things a little bit differently. I used what I call the Shape Abstraction Method instead of the better-known Loomis Method. Shape Abstraction starts by mapping out basic shapes and values, which we then refine and add detail as the sketch develops. What do you think? Should I stick to Shape Abstraction or go back to the old Loomis Method?