I don't get how making note of the input lag makes it not noticeable...
... sounds like that's the one quality it should lack for that to be the case. Less input lag doesn't mean unnoticeable.
He's just pointing out that of COURSE there's input lag. He just can't notice it. You use tons of gaming peripherals with input lag and don't notice it.
Now I'm personally not going to be on board with the idea of Kinect 2 until I hear from many sources that the lag is unnoticeable, but this is a good start.