My STS' transmission is awful! When downshifting, it has trouble finding a gear, especially when you want to re-accelerate. It makes for a very rough ride. At speed, it's okay. Also, its voice recognition is poor. The electronics are too complicated, too. The learning curve is fairly steep. I also don't like the adaptive cruise control. Bluetooth is a joke as well.
The heated seats. They work well.
So many things, so little time. Fix the transmission. Then rethink the navigation system etc.