I'm very happy with SilverFast for my Canoscan 8800F. The results are way better than what you can achieve with Canoscan.
And is this a surprise ? SilverFast is a professional software many photographers rely on.
SilverFast has unique patented techniques, it has won the EDP award for the best color management software in 2008.

Hmm, I can't understand some of the comments below. Maybe they used very old versions ? Ok, they were written some years ago. They developed a lot of new features (look here: http://www.silverfast.com/show/scanners-canon/en.html) in the meantime. I don't know, if it was slower than Canoscan that days, but these days it's not, it's fast, it's silverfast :)