I agree with John. However, I abandoned film several years ago and went digital -- except for meteor photography, which I still do with print film.
I did use slide film a lot however, particularly for wide-angle and night-landscape / startrail shots that I used in presentations. However, the new DSLRs are so good for these purposes, and presentations are now almost exclusively all-digital, that I see no reason to continue using slide film.
I have successfully used flatbed scanners with adapters for slides, but as John says they're not optimal for that purpose. Their resolution is low and/or digitally enhanced (meaning interpolated). I later started having my film scanned at a color lab and they did a wonderful job.
When I use print film for meteor photography I got through dozens of rolls per night, so the scanning gets pretty expensive. I use a custom lab to ensure the film is not cut and then I use a loupe to find the frames with meteor tracks and have those scanned to CD.
The main problem I've found with having labs scan negatives or slides (even custom labs) is that they don't always use clean scanners, or clean the film before scanning. That leaves spots and debris in the images ...