Have had nothing but joy from the Nikon Super Coolscan 4000 in my office. I believe that Nikon has essentially discontinued all their film scanners, and I have to run it on an older Macintosh (running Panther) to get it to work, but nothing I've seen scanned with an attachment on any flatbed scanner has come close to the quality it attains. There are a couple of newer models, but all of them seem to be, if anything, rising in price on the used market now that Nikon doesn't make them anymore.
If quality is really important, you might consider getting one, using it, and then re-selling it when you're done.
SSB