this is looking good Marc!
@Henry: increasing the gamma to 2.4 is not a good idea. It would just make the render look greyish. Instead, it's better to reduce the contast in the render node, maybe increase the power of the AO helper light (slightly), and render with high GI settings, such as 2/4, and use a render quality of 0.8 or above. This way Marc gets a lot of details in the shadows, which he can fine tune in post.