I've blocked in these facial expressions to see how far I can push my character's face deformation as well as testing Maya's dynamic hair setup. The render consist of three layers, the background, the character and the hair. The character and hair shadow is rendered with Mental Ray. I've started the hair render with Mental Ray and p_hair_Tk shader pack in Rasterizer mode initially, but had to change to software-render to bring down the render time from 9 minutes to 3 minutes per frame. I would have liked to decrease the hair width and raise the hair density, but that pushed the render time to an average of 7-8 minutes per frame.
The other issue I ran into was an offset between the Mental Ray and the software-render layer renders due to the 2DMotionVector pass applied to the character layer. The solution to this apparently is to switch on motion blur in the software render settings, but this raises the render time with about another 3 minutes per frame, so no motion blur applied to the hair layer, I had to manually fix the offsets in comp.
One more issue is the flickering caused by final gather when rendering deforming geometry. I might fix these issues when time allows. A major PC upgrade will allow for better quality renders in much lower render time, hopefully soon ;)