Awesome job- 1/72 is very hared to do as I've found out- I stick mostly to 35mm and some 28mm. Are you part of the yahoo groups sculpting group? If not join- you've got great skills don't let them go to waste!
not bad. Some tips: Basic anatomy. The arm looks longer then the legs, which makes the figure look childlike.
Also, aside from the basic shape your #1 priority is a smooth and even surface. for example, the shield should be much smoother. This requires a light touch and a well lubricated tool. You can also use a lubricated paintbrush for final smoothing.
From the looks of the shield you made it all in one go. It is easier to sculpt the shield without detail, get it nice and smooth and let it harden. Then, add the upper and lower edges, let harden. Then carefully, add the tree