This is a simple comparison between a dedicated film scanner, the Plustek OpticFilm 7300 and a Canon 9000F.
Unless the Canon has improved significantly with the newer 9000F MarkII, this remains valid.
I shot mostly 35mm and I have a few tens of thousands of slides. I also have 120 film and a medium format camera, so I needed something to scan both. I got the Canon because funds were limited and I needed a scanner under 200.
I was disappointed with the quality of scan from the 9000F scanning 35mm. So recently, I managed to get a Plustek for under 120.
A serious difference. Like between a VHS tape and a BluRay Disc.
Example – from the Canon: full frame

Zoom into the eye, and see how soft the scan is (click to view):

Now, same slide from the Plustek Opticfilm 7300:

Now, zoom into the eye (again, click to view):

Yes, what appears to the untrained eye as “noise” is actually the grain from the film. This is what I expect of a good, sharp 7200 dpi scan of a slide!
This is Kodak’s Ektachrome 100SW. This is a reversal film, which produced a positive color image without needing to be printed.
The 7300 doesn’t have any scratch removal hardware, but I had a Nikon LS-200 from 1998 until it died in 2006, and when it removed dust the resulting image was often soft… and it never worked on B&W film anyway.
You have to move each slide into place and start the new scan, but it’s easier to use than the other sub-$500 scanners on the market.
This will do until I have the funds for a Nikon V!!