This is the first image the author developed from the X1's DNG file. The RAW file gives gobsmacking details and clarity in the image. It is visually much, much better than the jpeg file. No scientific comparison was done side by side between the GXR A 12 28mm module and the X1 for the image quality in their RAW files, but it would be more likely to hear oohs and ahhs when one sees those from the latter.
Google-translate this in case you wish for some lab test results.