Here is the GRDII/GX100 ISO performance comparison. Few comments..
The 28mm seems to be not the same in GRDII and GX100, hence the difference in angle of view.
The closest GX100 aperture to GRD at 28mm is f2.7 (GRD is at 2.8).
All JPEG settings are set to 0 (default).
DNG files processed with dcraw using these command line parameters: -w -W -f -q 3 -T
I believe this sequence provides probably the best (and neutral) image quality. Other RAW developers are doing more or less optimizations, which affects the image output. So I've decided to go the dcraw way. In fact, most of RAW development tools are more or less based of dcraw ISO 400ISO 800ISO 1600My conclusion:
GRDII RAW is slightly less noisy than GX100 RAW.
GX100 RAW files contains some "hot" pixels that are not visible in GRDII RAW files. This is only a small example. The GX100 DNG files are full of these small spots. But of course, they are only visible at 100% magnification (aka pixel peeping)
GX100 preserves a bit more highlights.
GX100 JPEG is over sharpened (my recommendation is set sharpening to -2)
GRD2 JPEG is heavily processed with NR, even with NR set to OFF. The NR artifacts are visible in all shots above ISO100.
From what I've seen, I tend to believe the GRDII uses different sensor than GX100. Maybe just another generation of the GX100 sensor, which is less noisy, but also less highlight friendly?
Full resolution images can be downloaded here:GRD2 DNG
to extract the 7z files, MAC users should have to use one of >these
<)R0012151_80.7zR0012152_100.7zR0012153_200.7zR0012154_400.7zR0012155_800.7zR0012156_1600.7zGRD2 JPEGR0012151_80.jpgR0012152_100.jpgR0012153_200.jpgR0012154_400.jpgR0012155_800.jpgR0012156_1600.jpgGX100 DNGR0012107_80.7zR0012108_100.7zR0012109_200.7zR0012110_400.7zR0012111_800.7zR0012112_1600.7zGX100 JPEGR0012107_80.jpgR0012108_100.jpgR0012109_200.jpgR0012110_400.jpgR0012111_800.jpgR0012112_1600.jpg