Hi, V8Beast. Some great shots! Thanks for posting.
I, too, had a bit of a panic. I went to an event the day I got my camera, set it to aperture priority, and everything was shooting about 1.5 stops under. I have been so busy over the last week that I have not been able to do much of a formal test yet, but fortunately, images I'm casually snapping are coming out with more reliable exposures.
Is 5DC shorthand for the original 5D? If so, I had that camera, too and skipped the Mark II to wait for this one. The original 5D rarely had issues with needing exposure compensation.