the GR DIII is certainly OK,
...but I wish your tests were a bit more documented. I assume you shot your pictures in jpg, and what they show is a pretty good handling of the NR algorithm by Ricoh's engineers. I'd have liked to see a downloadable raw sample to make up my mind, as cameras of this class won't be set to jpeg most of the time. Further, a raw would have shown the expectable level of noise that's been wiped by the in camera NR process. A general 'softness' in the 100% crops is a tell-tale sign of this.
Oh, and while I'm at it, stop shooting your door knob for the iso settings. The mostly uniform blue background is a free gift to any self-respecting NR algorithm, as it makes its job much too easy ; better have a pint at your local pub after 8 PM and shoot indoor. Don't forget that tripod to offset the lager parameter though, it would be bad science otherwise.