Great work there guys! I just did a quick comparison of my K20, GX20 and K7 at ISO 1600, with no NR and various NR setting. I'm basically getting similar results as the pictures posted here.
One thing that bug me on my K7 high iso picture is the size of the grain. It seems to be rough, and bigger than K20 or GX20, no matter which NR setting I choose. Eventhough I don't see noise like in K20, the rough grain seems to make the picture seems not as sharp as K20.
Maybe I peep too much?
Other than the grain, everything seems perfect for me so far.
Mike