Lots of good info, thanks.
I've confirmed I can get it for $200 with everything original and an extra battery, which suits me fine. Don't feel the need for the grip and Lplate, which will be taken out of the deal.
The appeal is that it's only $200. It's not been used much (was a backup cam) and it'll probably sit around a fair bit in my drawer and bag. And I can get it locally with no tax, easy, etc. I was prompted to get it because I have a ski resort shoot coming up (I don't do a lot of paid photo gigs) and I just don't want to risk standing there looking stupid if the 6D does something unexpected. And my backup to the 40D in a pinch will be the Sony RX100 which isn't a bad third-string fallback if desperate.
I will test it with my lenses to make sure there isn't any focus adjust required. That sounds like the main limiting factor on the camera. I'm used to a brick camera with good low iso, having used Sony a700 and a850. Feel like I know what I'm getting into. Heck the 40D might be preferable to the 6D for some outdoor action shooting...