It's a very good deal - 40mp backs are hard to sell at high prices, since there are a few DSLRs at that resolution already.
Credo is much nicer than Aptus - however note that it gathers much more sensor dust. With Aptus you can go months without cleaning, with Credo I need to clean every couple of days. I would say an electric design bug probably shared with IQ. Credo colors are more accurate but less punchy. Credo is 1/3 stop more light sensitive on same ISO, and slightly less noisy.
DF+ is supposed to have much better MTBF, I could not find many other differences to DF (easier live view, but live view works well only under very strong light).
80LS I found the same quality as 80D, I didn't check wide open.
If you really hate dust, you might want to think about a used Aptus for a lot less.