Thanks a lot for the replies.
Yeah, I see that slight horizontal smudge in your photo, but it's not really objectional, at least for most uses on the internet. Speaking of the internet, why post perfect images-they're just going to steal 'em and post them on their own obscure websites without our permission anyway. Oops, sorry, went off subject.
My impression is that if I am willing to manually remove the defects from scanned Kodachrome and B&W then I could use several of the current scanners with satisfactory results.
The only contamination problem I have with my slides is occassional loose dust. I learned to remove this with compressed air before having them scanned to PhotoCD. I don't think any image improvement occurs when you have your work scanned to PhotoCD, at least not at the price I am paying. So I'm pretty familiar with having to look for dust in the image anyway. Its really part of self-imposed quality control, and I think all of us practice this. Or we should.
My B&W negatives have always had more spots and contamination on them than my slides. It doesn't seem to matter who develops them, the B&W negs often have small spots that appear white on the print. When developing my own negs, I installed a water filtration system because of this, and that didn't seem to help. So I started using distilled water, and that didn't seem to help. Eventually I lowered my standards and went to commercial development.
I still doubt that I have the additional time available to spend it on the computer using a slide/film scanner. It would be another case if I had several paying customers who demanded quick image services, but at present profit motivation is minimal.