The rig works well to provide flexibility in the mouth, eyes and neck area and uses bones to control the eyes and nose as well as blendshapes to deform certain areas such as the eyes and mouth. In the final rig, this allows for such detail as the rolling of the lip, which wasn't implemented in this character as the cartoon style lends itself to simplicity. There are some flaws around corners and joints but the polycount on the character was relatively low compared to the test example used. Smoothing solves many of these issues but it may be more prudent, in future, to look at the concentration of vertices in crucial areas
It's eyes move well enough, but the lack of controllable eyelids limits the extent of the facial expressions that can be achieved. Again, although colour was not necessary to create this model, it would have been a nice feature to see.