I have the following....and offer scanning to other members of APUG at a discount

(shameless self-plug)
Nikon 9000ED
Nikon Coolscan 4000ED
Imacon Flextight Photo
Betterlight 6000 Scanback (for glass plates, larger artwork, etc).
Epson V750 Pro.
I love scanning with both the V750 and the Imacon Flex. The Flex usually does my 6x6 and 645 whereas my 750 does all my 4x5. The 750 pro comes with a "wet mounting" scanner tray for doing wet mounted scans with Kami fluid. I rarely do so, but sometimes with a 35mm or 6x6 it increases the sharpness and removes some defects that may have arisen from um....user error....in the darkroom hah!
The Flex does a great job with DMax and with sharpness due to its method of bending the film as it scans. My Nikon 9000 and 4000 have been relegated to my batch work for clients who need "quick and dirty" scans using auto correction and Digital ICE--image correction and dust removal. This speeds up the process so they can come back with individual frames they want hand adjusted and scanned.
As Ralph says above there are some better holders now for the 9000 and 8000. There are a ton of options from Nikon and there are some modifications that one can do to make them even better than the factory models. There is even a model for wet mounting medium format that I'm looking into. For the V750 (and others)
www.betterscanning.com makes some wonderful aftermarket film holders as well....
Happy shooting....and happy scanning!