Perhaps the most interesting portion of the exterior design is the still-incomplete robotics lab (photo). With its shiny metal exterior, separation from the rest of the building structure, and conical chimney, it almost seems like a cottage to the rest of the building. In most of the sight lines for the building, it seems to stand out most prominently, which perhaps was the intent of Gehry when he chose for it to be the shiniest.
In comparing the Stata Center and Disney Center, I would say that the Stata Center has a much slower rhythm. When I visited the Disney Center, I found myself taking a photo, walking two feet, and finding a completely different view that I had to take another photo of. The variations in the Stata Center design are much more spread out, and while it does have a greater diversity of design elements, it doesn't have as many interesting angles from which to view it from.
Related: Index of other Stata Center entries