..."that awful 1-series body"...are you serious? You're sounding a little like someone who has never worked with a 1-Series EOS body.That camera is called EOS 1Dx.No, the 1DX does have fast frame rates which I'm willing to give up and it has that awful 1 series body which I will never buy or even consider.
If you work with cameras on a daily basis, settling for anything less than a 1-Series body can feel like a compromise, especially in a dynamic shooting situation. Mind you, I'm not saying that non-1-Series bodies are flawed, it's just that the 1-Series is so far out in front it's not funny. You definitely get what you pay for.
edit: FWIW a gripped 5D3 is taller, thicker and slightly heavier than my 1D4