This raises the questions that perhaps Sean's tests will answer: at which point in terms of print size will the extra sharpness of the GRD2 make a compelling difference?
—Mitch/Huahin
And first we need to know how much of a resolution difference there really is between the two, at various apertures. Your comparison suggests that the GR2 has a higher contrast lens, which creates the illusion of higher resolution, but which also lessens effective DR but raising the noise floor. I have a hunch that GR 2 lens might tolerate smaller apertures better than the GX100 lens but I'll need to test to see. If I recall, you've been using the GX-100 a lot at F/5 - F/5.6 and its soft there because of diffraction. The GR 2 may be different.
I've requested the GX-100 test camera for comparison and will do the comparisons when Ricoh sends me the "40" add-on lens - maybe next week.
If a lens responds particularly well to sharpening, that suggests that resolution, but not necessarily contrast, is good. The increase in local contrast (sharpening) can make that resolution more apparent but, as we know, it can't actually ever add resolution.
Cheers,
Sean