I am a bit surprised to see you sold the 5D II with all that investment in glass. I would have thought, the way even a 5D Mark I is keeping value, that the timing of sale of is less of an issue. Due to the high price of the new 5D III, I am thinking that a bit of extra cash, that you may or may not get, is minor compared to not having a body to use all those lenses with. Especially if you now buy a G1 X.
Even if Canon produce a CSC that a ff body would be useful to have around. There is a particular value in a ff and it would fill the role where the CSC falls short, ie dof and low light and focus ability, as you explained in your link to the other post.
When I read your posts, part of me was thinking that selling a couple of your lenses may have been a better option, you did make reference of not needing the dof required but wide angle would be useful.
Is it possible and dare I say it, it seems to me you are having a total philosophical shift and you are sick of carrying the big thing around and you are using physics and logic to justify it, when its contradicting you to some extent. I guess I am looking at it from the other side, I am down under after all.
PS: It seems logical to me that Canon will build a CSC around the sized sensor in the G1 X ( beats Nikon and more or less matches 3/4), therefore 24-105 F4 on a ff will not really be matched by a CSC, since even a 2.8 on a crop sensor cannot match it, as per your above link.