The original skateboard frame had some issues. It was easy to have the end of the board hit the ground while riding up hills. The squarish design would drag a corner while making even moderate turns. There were also issues with accessing the internal electronics and controllers, making it difficult to quickly update the software. The skateboard itself was quite heavy, weighing about 38 pounds. That made it difficult to lug around, especially with the lack of a good place to grab it.
On the other hand, there were several aspects of Skate One that worked well. I wanted to keep the good stuff, and upgrade everything else. If you're interested in the details of the first skateboard, read up on it here.