Hey Brad,
That is looking really good!
And kudos for re=doing the excercise 💯
You have 1 heavily distorted Quad (its neighbour is also slightly bent) here:

but the Subsurf Modifier ‘fixes’ that. 💯
Some minor points:
Two triangles that can easily be fixed if you want, are those N-Gons at the corner of the mouth? and a 6-sided Pole:

But all these points don’t cause any problems in the Subdiv Model, so good enough!
Again, I must say: great work 👍🏻