The problem with comparing the two is that CT 8.1 and CC use different render engines. Lighting has an effect too, as well as any conversion to PBR.
Flipping Y makes a difference, but it is hard to say which one is more like CT 8.1. In one case I found the overall shape of the lips much better in CC, so there is some conversion going on, in this case for the better. Also, after importing the head, there are many ways for refinement in CC, such as pores, wrinkles, etc.