Steves digicams main page
http://www.steves-digicams.com/hardware_reviews.html has links to reviews and sample images from D1, D1H, and D1X. Click DSLR tab on the reviews screen.
Unfortunately although there are some of similar scenes different quality lenses were used which clouds direct comparison. Having spent time looking through, my opinion is that the D1H leads over the D1, and the D1X naturally leads over the D1H in terms of resolution.
Saving a D1X image as 10mp has big effects on file size.
Standard Nef 3008 x 1960 is 7.9mb resulting in a 33.97mb Tiff
Larger Nef 4016 x 2616 is 10.5mb resulting in a 60.23mb Tiff
I did the uprez in NC4.4.02 and compared it with a CS upsize to the same dimensions. I feel NC did a better job so there is something in Nikons algorithams.
Once again different quality lenses in use, but I will stick with the assesment that I made years ago comparing images at native resolution. The D1X is ahead of the D100 by a nose. Just could not afford the D1X at the time.
Don