I don't think a comparison of these two models is really needed. Also, Imcold's is ready to go, but they are in a sense two very different models. UHU's, with all the inside detail would be awesome for the centerpiece of a diorama, with Imcold's parked right next to it, ready to go.
Point is, two brilliant designers giving their work away. Who's to say which is better. One is done, the other isn't. Even then, they will have differences. Maybe be interchangeable parts, would be really interesting.