Command of the huddle, zip/touch on balls thrown at all levels, knowing what checks to make and when. These are all things I've heard consistently about Kizer thus far. The momentum with the "smoke" is getting stronger towards starting Kizer out of the gates, which is what I think gets everyone excited.
Kizer still must work on his footwork in the pocket (which isn't terrible) and accuracy on short throws. I'd guess he has decision making improvement to be had as well. As others have said, though, it's Kizer's physical make-up that is also getting folks excited. He's a big dude.