The GE was our first modular as well but as most in this thread thought we felt an expansion was in order. Ours was due mostly to a hole in our city layout next to the GE. In order to fill it we had to turn our expansion into an 'inside corner' giving the new layout an "S" shape. While the exterior is just an extension of the existing facade we really spent some time on the interior of the shop. You can check out some pics here: MOCPages, Flickr, & our little site. We were pretty pleased with the end results.
Some Individual pictures: Exterior Shot --- Ground Floor Interior --- Top Floor Interior