To the point
About the 6d,
I'm reading really bad reviews about the camera and its build qulity and I fear that I'l be missing the "Canon Feel" Which I loved so much and the reason I never Used Straps. you might think that thats stupid reason to judge camera and not by her specs But Had really Good bonding with my 7D =)
So i had the same fear but after buying the 6D i can say that it feels just as sturdy as a 5D/7D. The bulk of the body is magnesium and feels rigid while being significantly lighter. My only gripe with the build quality is the top plate plastic which feels pretty cheap, though its necessary for the wifi and GPS.
I had talked to canon tech support about the weather sealing and they had this to say if it helps:
"The weather sealing of the EOS 6D is similar to that of the EOS 7D and the EOS 5D Mark III. It is both dust and water resistant. The overall body design EOS 6D is similar to those two cameras. However, note that unlike the EOS 7D and EOS 5D Mark III, the EOS 6D front and rear covers are made of a Magnesium Alloy and the top, side, and bottom covers are made of a Polycarbonate resin."
Also, I loaned a 5D3 and used it with my 70-200 f/2.8 and it did not have that issue, neither did my friend's.