MR has has an acrylic display case, HC does not. MR has some really poor weathering applied with felt tip pen, but can easily be removed. HCG has the batteries in the rear of the main unit, and as previously mentioned, the Hama viewer plugs in via a 3/4 " jack plug. MR Hama viewer is attached to the main unit, and the batteries are in the viewer itself. Other than that they look pretty close, but I haven't got direct experience with an HCG. I would choose the MR over HCG if the option was available, best licenced prop I've owned. HCG products have had numerous issues.