I remember trying to do this with force displacement and didn't get the results I wanted, and Matt told me about the mesh displacer, but I didn't have access to that on freeware at the time. I long forgot but it just dawned on me this morning, so I did a quick test and thought I'd share for other users.
They don't look to bad, unfortunately I couldn't get any surface detail to show through with default or ray traced, oh well. Force Displacement you'll get broken normals and tears unfortunately (so I mocked it with some texture noise). But based on tiny sphere object, not bad.