I know we've touched on brightness and contrast already, and they'd help drasticly in seeing what noise you were removing, but if you add these two, please also add saturation. Saturation is extremely useful as you can see the chroma noise more easily. One of my biggest reasons for using products like Neat Image is so I can color correct/saturate an image. If you use a digital camera, doing these operations is inherently limited because of the noise components on the chromacity.
You could do the noise reduction after the color shift/saturation, but I get the feeling that this would degrade the image as now the perceptual colors are more disjoint. I.e. shifting blues into the yellow spectrum. Perhaps adding hue would be handy too, but I don't see it as quite as necessary.
