IMHO the 7D is a better all rounder than the 5d2. It does every thing pretty good. It has CLS which the 5d2 does not. I have gotten to really enjoy the CLS function of the 7d that I have started to bring it to more portrait shoots.
If you don't need a fast agile AF system, 5d3-esque ergonomics, CLS etc and are a centre-pt recompose person, then the 5d2 will meet your needs. Plus the ability to shoot low light.
In terms of IQ, I cannot see a difference b/t a 5dc and a 5d2. But the later does have higher ISO capabilities, larger MP and hdslr.