Dynamic range through NR reduction (i.e. through detail loss) is not real DR. If you think it is, then I will give you a secret recipe to maximize your DR: apply to all your pictures a gaussian blur filter with 20 pixels radius. All noise will disappear at any ISO so your DR will be stunning. But please don't complain about loss of detail because that kind of DR is what you wanted.
That's true, and this is where Quentin's method of visual comparison of real-world images can be effective, provided identical scenes are used under the same lighting conditions. If Camera A produces noisier but more detailed shadows than Camera B, then this fact should be apparent in real-world images. If it isn't, then the fact that Camera A is noisier but more detailed, is of no consequence, although it may be of academic interest to some and it may well be essential information for those who are producing their own RAW converter or noise reduction program.
I'm reminded here of Jonathan Wienke's DR test target (downsized version below) which I downloaded over a year ago, took a few shots comparing the DR of my 20D and 5D, then spent hours arguing about the necessity of comparing DR at the pixel level as opposed to the scene level. My view was, and still is, that DR at the scene level is what's important to me, although pixel DR is of some academic interest.
For example, I find it interesting that, according to DXOmark tests, the SNR and DR of the 5D MkII and 20D are approximately the same, at the pixel level. In fact, the 5D2 is sometimes very slightly better in DR by amounts of approximately 1/4 EV, which are not significant in my view. What is significant is the substantially better SNR and DR of the 5D2 in normalised prints, or same size and same FoV images on monitor.
The pixel size of the 5D2 is very close to the pixel size of the 20D. It's interesting that, after a number of years of development between the release of the 20D and the 5D2, so little progress has been made in improving the SNR and DR of the pixel. I would deduce from the DXOmark results that any image taken with the 5D2 that was cropped to the same FoV one would get if one had used a 20D with the same lens, would be of approximately equal quality to the 20D shot. Whether or not this is true can also be determined by visual inspection of real-world images.