Nice plug for Vuescan and SilverFast from Bruce Fraser on page 4 of his article:
Cleaning Up with the Nikon Super Coolscan 4000 ED
If you really want a workflow that relies on raw scanning, you may be
better served by driving the Coolscan 4000 ED with a third-party driver
such as Ed Hamrick's excellent VueScan, or LaserSoft's equally excellent
but rather more expensive SilverFast.