I've put up two files, processed to look as similar as possible, and incidently exactly how I wanted them and how they went to print.
They were shot at within a half stop of perfect exposure, Canon 1Ds, 17-40L @ 34mm 1/80th at f5.6 and Metz auto flash with lightsphere II handheld. WB set in each program using a Whibal.
Neither have had any sharpening, the RSE had sharpening set to -50, ditto detail extraction, ditto noise reduction. Colour noise reduction was set to +50. These are uncompressed jpgs straight from the raw convertors.
The RSE colour is straight out of the can, the ACR using a custom profile.
Keep in mind that these are full size 1Ds files converted from RAW to jpg and are big!
Make your own conclusions as to the whether it's detail or sharpening on the RSE file, apply USM and see what you think. Personally this is the picture which I used to come to the conclusion vis a vis sharpening and colour noise.
If anyone is interested, the picture is of two Rabbi's talking at an engagement party. On the left is my old Headmaster, on the right, the head of my Yeshiva (Talmudic college), both wonderful and warm personalities.