generally the 1st drawing is better than the 2nd - which is why I rarely do actual studies for paintings
redrawing some notes from Michael Mentler sketchbook over some old sketches of some girl at the library
His sketchbook drawings are very cool & show the anatomy constructed up from the bones (from memory), which I had never seen before - constructed through anatomy and not just geometry. He does suffer from what the majority of Master Anatomists paintings suffer from - they lack emotion or creativity and are generally little more than refined drawings in color.http://www.michaelmentler.com
http://conceptart.org/forums/showthread.php?t=72362
Eventually, I will know and understand all (most) of the anatomy he does. The way I use them, knowledge is basically being aware of info, while understanding means that you can do it as well or have personally experienced it. When you know more, it increases your potential to do (draw/paint) better and greater work, however greater potential/talent it's a double edge sword. I'll go into more depth some other time.