I did, actually, after I posted that, and it's the same. Just didn't think it was worth coming back saying that I did, since there's no difference. CCC settings might get stuck in the registry, but this is actually an extra option on CCC panel (among other extras that were also there) for the 5000 cards, so it's very unlikely that not cleaning the newer driver would have gotten those options stuck, since CCC gets also uninstalled.
Right now I'm gonna be testing with Realtek 2.35 which was the driver I was using with the 4670. Lose bitstreaming of TrueHD and DTS-MA though.