There were _some_ improvements. In general, Unity is stable, fast and adjustable, but it lacks polish. Its size, inability to provide decent management for absolute paths (I have more favored applications than allowed by Unity default space, and I like them in groups, just fine) make for quite bad user experience, even with improved System Settings menu.
I wish I could access my little app park the same way I can do that with System Settings...
Anyway, there are fallback options, without Unity. They work fine and provide missing functionality.
In general, system feels a little faster than 10.10.
Regards,
Ruemere