One very bad - and in the end also positive - experience.
I can now testify, that the 6D body has proven to be absolutely robust and solid.
This is based on a nightmare type of experience (could also be reported in the post about 'dont ever do this'):
I was setting up in my basement for a special shoot in the garden using a Canon 24 mm TS/E and tripod.
The camera with the TS/E was mounted on the tripod at about 4 feet above the concrete floor.
Then I moved the column of the tripod to a horizontal position (my Manfrotto tripod allows that) and turned around to fix something else. Then a heard a grueling crash. The tripod had tipped over, and the camera hit the floor.
Stupid me overlooking that the center of gravity had shifted slightly outside the support of the tripod.
Examining the camera and optics, I noted that the whole setup had landed on the upper right corner of the body, and there were marks from the impact on the floor as well as on the 6D body.
No dents - only paint-scrapes. The lens did not show any marks, so the camera took the full blow.
With shaking hands I examined the camera further, the lens, the mount etc. Nothing visibly affected.
Then testing the function of both - all seem to work perfectly well and normal. And they still do. Even focus as well as image sharpness over the whole image seems to be unaffected.
Conclusions:
1. Now I have tried it - so you don't have to do it yourselves.
2. The 6D body - including the upper part which is said to be made from some sturdy plastic material - is rock solid
3. The 24 TS/E did well, too.
4. Considering the weight of this lens, the mount between lens and body stood the test as well.
5. The laws of Newton even applies for FF bodies - and for TS/E lenses. (although I am sure he did not consider that specifically). So I will not challenge those laws any further.
If you have any suggestions for what to test further - and how - to verify that the equipment is actually not affected in any way, please suggest these to me.
PS: As to the other virtues of the 6D I have posted my (less grueling) experiences in other posts - I guess all of these are linked above.