I know that the copper coating will degrade, but this seems to be a problem with the manufacturing process regardless of whether it's CCA or OFC. I've seen OFC wires with severe corrosion in the middle of the run, rendering that whole expensive copper wire useless. The degredation of the copper coating on the terminal ends of CCA wire are a non-issue due to the length of the exposed surface.
Until I'm shown otherwise, I stand by my original statement in that if the electric current carrying apparatus (wire, lol) is built correctly for a specific amerage rating, then it will do the job with no problem. Steel, copper, aluminum, banana, doesn't matter.