Why not both?
There are time I do both, one is sometimes more convenient than the other. It's nice to play a game, then watch a movie, someone comes to do the door, just say, "Xbox Pause" and deal with them.
It's like texting on my phone, I usually type stuff in, but sometimes it's better or more convenient to dictate it.
Some people just need to live with Kinect for a while before they really see what a new world it opens up.