the quality of the sharpening process depends greatly upon the quality of the interpolation of the original RAW file.
Great point -- This is so important it cannot be understated.
In this respect ACR3.1 produces much better edges than any of the other RAW convertors on the market at the moment and can be sharpened to produce a much more detailed image.
However, I totally disagree with this. ACR3 may be better than anythiing else available for the Mac, but RSE is a better converter for edges and detail, hands down. IMO even C1 produces better detail than ACR3.
Sidebar note to the above: I had a long-time LF shooter tell me that he was disappointed with results he had seen in large prints from high-end DSLR's. Since it is well-known I print large, he asked my opinion. My reply was "a picture is worth 1000 words," and I sent him an 8x10 crop from a 36x54 print made from a single 1Ds2 file. That file was converted with RSE, sharpening on and set "0". The file was then processed and sharpened with Smart Sharpen (one pass at 1/150) as outlined above. The image was then upscaled per my previously explained routine, and the crop printed. Anyway, to the point -- when he saw the crop, he immediately ordered a pair of D2x's on the spot (he was a Nikon shooter from before) and put his film gear up for sale.