A capability study of Freestyle (Blender 2.69) was done using a 3D model recently released at http://www.yukicocp.com/.
The image to the left is a simple render composed of silhouettes (thin lines) and external contours (thick lines). The image in the middle consists of the same silhouettes and external contours as well as suggestive contours (dotted lines). The image to the right shows the mesh data (841K faces) imported into Blender. No textures were included in the original 3D model (specifically prepared for 3D printing), so that only the shaded surface and auto-generated lines are shown in the Freestyle renders.