Adapting / front / back focus by lens (AF_Feinabstimmung)
Manually adjusting the autofocus regarding Nachführverzögerung and focus priority
Individual camera settings (C1 and C2 on the dial)
Bracketing with 3, 5 or 7 recordings
Merhfachbelichtung
These are the most obvious differences. I bought the 6D due to the full-frame sensor. A 5D Mark III was me simply too expensive. I fall clearly in the Target of Canon audience, so it seems. The Canon 60D has built not only a full format, but an upgraded version with professional features, makes things better all the more.
Thus I see the camera as a next step to a 60D, and I'd see a 5D Mark III as a next step to 6D.
The auto focus, which often comes in for criticism a result of a cross-type sensor, me so far is not misbehaving with my kind of photography. However, I must say that I little fast moving things Scan. When photographing I notice personally to now no difference to 60D in the application.
A few more words about the WLAN function. If you understand it, as Canon has implemented what is added some getting used to, it's a fantastic thing.
First, you can connect several mobile devices with the camera. You can take the camera into an existing WLAN or they can be set up an ad hoc network. The latter is very useful when you are outdoors. In addition, you can connect the camera to a computer, so that the camera can be controlled remotely without any problems (almost all the necessary with the EOS-Utils functions). These are in the camera's various memory locations are available, so that you have quick access to the settings that you need now.
The smartphone replaces the folding screen. I'm not a friend of folding displays. Too rarely do I need the function, built-are dearer to me.
All in all, the 6D for me a triumphant upgrade to my 60D. It feels like that. I did not feel the need to make trade-offs as compared to 60D. Course by the 5D Mark III room for improvement, but this must also be paid a much higher price.