By chance, I recently noticed a difference in resolution between the original Olympus RAW .ORF file image, and its .dng version. Today I used a best quality print of the ISO B&W resolution chart to make a full frame image using my Oly 12-40 2.8 PRO lens on the M10. The resolution is impressive, but that is not the point. I used DNG Converter to make .dng files, Olympus OV3 to make .tif files, and also FastStone IV 5.5 to make .tif and .jpg files. All were derived from the same .ORF file.
Only the .dng image compared poorly with the original .ORF image. The test chart allows a comparative score of 1 to 20 lines per picture height.
My score for the .dng derived image was 9 or 10. All others were 13 or 14, and the difference is quite distinct.
DNG Converter is good and easy to use, and is excellent for recovering shadow detail, but in future I will use it only as a last resort to rescue an exposure error.
My comments refer only to its use with current Olympus .ORF files. Its repute indicates that it works well with all else.