Where to compare dof between the 6D and 1D4?

Great Bustard wrote:

Like I've said from the beginning, so long as the FF sensor is at least as efficient, has at least as many pixels, the FF photo is not being cropped to the same framing as the camera with the crop sensor (or, if it is, the FF sensor has the same, or greater, pixel density than the camera with the crop sensor), and the crop camera is not using a lens that is 1.5x sharper than then FF camera, then crop will never have an IQ advantage over FF.

Or, more generally, with the exception of extreme macro or extreme telephoto shooting where the FF photographer must crop heavily, it is all but unheard of that a crop sensor camera will have higher IQ than a FF camera of the same generation (although there are certainly exceptions -- the D7000 has way more DR than the Canon 5D2, or the 5D3, for that matter).