I hate that I seem to be the only person on the internet with a 35% success rate on voice commands. I started out trying to use voice as much as possible. At this point though, if it doesn't work the first time, I just use the controller. It must not understand my accent, it's been so hit or miss.
I wish I had been spending more time with it to tell you what I think of the UI but between Forza 5, deaf kinect and how just uninteresting to look at the UI is. I have been spending more time with my PS4. Ryse was pretty fun though.