Ah, yes, my favorite spot. There are many improvements to the editor. The preferences have been expanded. There are new map features, such as rice paddies and barbed wire. The tiles have been downsized to the new scale so that nothing seems out of proportion.
Roads are strings instead of ribbons.
Buildings are placed in groups. Units can be picked to form multi-national forces. You can mix and match to your hearts content without changing nationality flags. In essence, you have access to the entire database of men and equipment. One of the real irritants to scenario design has been the impossibility of changing the number of units initially chosen.