I also use mine. I use auto sign in for my kids and myself. Plus voice commands for for watching tv, snapping apps, etc.. I am glad there are options now for those who refused to buy one with a kinect, but I am happy with mine.
I left mine in the box for the first month to use the system without it. After plugging it in I prefer having it. Using voice commands is pretty convenient. I wouldn't have bought Kinect if it weren't included in the system, but now that I have it plugged in I won't stop using it, I've come to enjoy the features and I never even use it for gaming.
Xbox on turns on my Xbox, my tv, and my surround sound. Phone rings xbox mute. Xbox record that when something unexpected happens. The auto sign in is nice. I admit i have not used it for motion controls but the voice controls are now something i do nit want to game without.