I have not tried this particular one, but while I am shopping for a scanner with a film adaptor for my office, Canon showroom staff themselves told me that the 660 isn't very good. They recommend the FS2400U instead.
Anyway, most of the lower end flatbed scanners with film adaptors can't scan film very well. The exception is probably the Epson Perfection 2450, which I hope to be able to get a demo soon. Not cheap though.