By the way, have you tried the option to use the full horizontal resolution of the D1x's CCD? I know QImage and Bibble can do this, and I thought Capture could, too. The result is a 60Mb 16-bit TIFF, but it means that the software has had to double the vertical resolution by interpolation. Even so the results I've seen (using QImage and a couple of trial NEFs) were very impressive with no obvious evidence (such as stair-stepping of diagonals) that this had been done.
I think you'll find the comparison between digital and film isn't an easy one. When you look at an image taken by the D1x at the pixel level you'll see everything is very smooth - obviously there's no grain, but there's also far less noise than you would see from even a good quality scanner such as your Coolscan 4000. There's also the fact that the image is the "first generation", while with film there will inevitably be some loss during the scanning process.
The question I'm interested in is not so much whether the D1x challenges film per se as much as just how close it gets to film and the type of scanner someone could reasonably own if they wanted to make their own prints.
Could be an interesting topic to launch the D-series forum with!