I can't comment on the 60D, but I have both the 7D2 and the 5D2. It's hard to pinpoint the ISO difference between these two cameras, because I feel like it varies over the ISO range.
In my experience, the 5D2 is about a half a stop better than the 7D2 with respect to high ISO noise at around 3200. So the 7D2 at 3200 has about the same amount of noise as the 5D2 at 4000 or 5000.
At higher ISO (12800+) I like the 7D2 better than the 5D2 because it produces a cleaner style of noise. At these higher ISOs, the 5D2 has a lot of chroma noise and it looks blotchy. The 7D2, on the other hand, has more luminance noise. It produces more of a sandpaper look without mixing the color, which is much more pleasing to look at straight out of the camera.
For both cameras I will set my auto ISO to choose up to ISO 3200. Beyond that I switch to manual ISO so I can determine just how far I want to push it for the type of photograph I am taking. I'll usually go up to around 6400, which isn't ideal, but not bad either if the end result is going be viewed at a smaller size.