David,
Many thanks. This will get me back to playing with the radius.
I virtually never use noise reduction. I find it isn't necessary at low ISOs on a crop (100 and 200 on my 50D; I haven't yet decided for my 7D) or up to 800 on the 5D3. What I do to avoid noise in the smooth areas is to apply a lot of masking. For bugs, I typically end up masking in the range of 45-65%. You probably know this, but if you hold down the alt key (or whatever is the equivalent on a Mac) while you move the masking slider, you get a gray-and-black rendition that shows exactly what areas are masked.
Re which body: in rough numbers, the sensor of the crop is 38% of the area of the FF sensor. That means that a crop of a 5Ds image to the 7D dimensions will have 22.1 x .38 = 8.4 MP, just under half the number of pixels as the 7DI. So, you need a lot more magnification to get the same number of pixels on the bug with the 5D3. So what I have been doing for now is that I leave my 7D set up for bugs, with a macro lens, usually a 36mm tube, and my awkward home-made flash bracket and diffuser in place. That way, I can just grab it whenever I see bugs, without spending 5 minutes assembling all the stuff. On the other hand, the 5D3's image is better in other respects, and a longer set of tubes would make up a lot of the difference.
Dan