Are Humans and Chimps Functionally Similar?

Continuing the discussion from Would God's Guidance Be DNA-Detectable?:

Turns out that @John_Harshman challenges this claim. I respond…

Does any one think that they can demonstrate in a salient way that Humans-Chimps are functionally more similar than Mice-Rats? Here, we are talking about function on an organism level, not biochemical. We are not looking for minor quirks here and there, but an overall pattern of increased functional similarity between Human-Chimps compared to Mice-Rats.

I grant that function is poorly defined. Does anyone think they can make the case?