Yes, it is amazing what some artists can do in their favorite tool of choice. I've seen organic models created with Sub-D plugins in SketchUp (my lightcycle tutorial an example) and all kinds of hard surface models done in Zbrush and 3D Coat. But to be honest, I think Michael has mentioned it before, but sometimes it's just plain easier to use a tool which is setup for a specific type of modeling. Just as one wouldn't use MoI to model cartoon characters for animation, I wouldn't use SketchUp to create organic shapes or even highly *iterative* detailed shapes like this one, which I believe much was done in MoI.