With D-Lighting using the "Better Quality" option gives you access to the highlight recovery control, without that you only have access to the shadow control.
With noise reduction there is a difference, see below a 200% crop of a section of dark overcast storm clouds, the structure is part of a refinery tower, don't try to spot any detail in the tower, it is basically a silhouette but you can see the edge detail. The settings are the same in both cases with only the quality options changed; you can see that the chroma noise has been brought well under control without making any other adjustments.
Here is the sample using the faster setting and the sliders at default settings for an image shoot at 1600 ISO, you can see that there is still some chroma noise.
[attachment=6390:attachment]
Here is the same using the “better quality” setting, using the same settings as the first example
[attachment=6389:attachment]
“Faster” again, this time with more aggressive settings, you can see that there is still some chroma noise
[attachment=6392:attachment]
And finally using the “Better quality” setting this time with a less aggressive setting than the above, you can see that this setting even set lower than the “Faster” examples does a better job dealing with chroma noise without a great loss of detail.
[attachment=6393:attachment]
Here is the same image with no noise reduction applied for reference.
[attachment=6391:attachment]
These images are not necessarily real world examples, but they do show a difference using the various settings and remember all these crops are at 200%. Also you will notice that Luminance noise has remained largely unchanged in all the examples, for me chroma noise is the only one that really is bothersome, while luminance noise reduction comes at too heavy a price in detail lost. There is no magic setting that you can rely on all the time, your going to have to make a judgment call each time but you can see that there is a real difference between the two settings.
The effect is slow to appear on screen, that is a the big problem I have with NX, a lot of functions are too slow to preview and apply, which is why I only use NX for my personal work and LR for the paid stuff, I can't afford to rely on NX when I'm on a deadline, even though it has better features it is just too slow.
