Stuart, what noise processing was done to these images? If they are shot JPG, what level of noise reduction/sharpness are selected in camera? (I can't ask about specific settings, as I don't know what the 70D's options are). Your ISO12800 shot, even viewed full size, looks like it's all luma noise, not chroma noise... usually at high ISOs the chroma noise is big, blotchy, and very ugly. These are nice! That ISO12800 shot's lack of chroma blotches, even in the shadows, has done more to sell me on a 7D2 upgrade than anything Canon has shown.