Phil reminds me of Phil.
I don't think a comparison to DK is a bad thing, except Phil is a football only kind of guy.
At this point (Soph year) I think Phil is about an inch-and-a-half taller, fifteen to twenty pounds heavier, has a better throwing motion, and a slightly more accurate arm.
With differences in offenses, etc., I cannot address any speed comparison, (not only are/were they both fast enough, they are/were a lot faster than people give them credit.) They have a completely different stride. The differences in their stride, make Phil look faster on film, but I am not sure that is the case. Peeps still don't know how fast Kizer is.
The other aspects, mental -- leadership I rate them both ten out of ten with what I have seen, and they both are obviously very bright and articulate. I don't know enough about Phil, but DeShone, is really intelligent, and quick to grasp, too. In any of these categories, I am not sure comparison between the two is necessary, because they both have enough to be deadly, even in the complexity of ND's offense.
Kizer never really gave away anything in high school, but Phil looks to be excellent with his eyes, discipline, and pump fakes. Beyond anything I would expect in a high schooler, let alone an underclassman.