One of the many things I really liked about v5 when I first started using it was the way it did NR at the default settings. Did I dream that, or have I inadvertently done something to bollix up my "default" NR settings?
It appears that v5's Color NR varies according to the image.
Looking at some base ISO RAWs for my 1Ds2, it jumps around between 42 and 47, and at ISO 1600 goes up to 48.
In contrast, the Luminance NR is constant at 25.
You can obviously manually tweak to taste, but it seems that the "default" is not a constant.