I have to concur with Teyon here.  Especially if you deal with animation, not just stills.  Shaping a good facial topology that can animate well with morphing, and look natural when emoting, is a challenge that requires special attention to edge flow.  Edge flow can represent muscle deformity, and make it look like there is tissue underlying the mesh that can move, and deform together, appropriately.  When a character smiles, it's not just the lips and eyes that need to look like they moved, but the entire cheek, and even the ears.  A lot of this comes down to rigging as well (most high end facial animation uses a lot more than simply morph changes), but the proper flow of topology is crucial to the entire process regardless.

I've seen a lot of animators send a mesh back down the pipeline because of deformation issues with the topology.  The modeller will almost always need to correct edges once the mesh is in the hands of the riggers and animators, if they aren't modelling the character with facial deformation in mind right from the start.

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Tools :  3dsmax 2015, Daz Studio 4.6, PoserPro 2012, Blender v2.74

System: Pentium QuadCore i7, under Win 8, GeForce GTX 780 / 2GB GPU.