I don't have a preference yet; still trying to learn more about them.
I think this class is wide open; from pocket passers to true dual-threat QBs.
As a Cougar alumni, I just have to include Clayton Tune.
There are several game films of his and the UH Cougars on YouTube.
You or anybody interested can just start with the highlights from each year.
They show a number of things he can do better than Mills like:
Throwing on the run, improvising when the play breaks down, throw across his body, throw while pedaling backward, run left throw right and vice versa, throw muddy in a tight pocket, etc.
He knows to look off defenders or freeze the safety for a split second, unless he knows the first read will get open.
Follow his eye movement after he takes the snap.