wow. I'm digging the SP/hand sketches. I really like that comic page you did. You keep getting better and better.
You've got a great sense of the volume when you're copying from life, but it loses some refinement when you start drawing from imagination. See if you can't develop some shadow patterns or do some construction exercises (ala Gaboartpage and Maxetormer) to develop that structure and throw some of those anatomical landmarks into alignment.
Looking friggin sweet, dude. Keep it up.