I have had my Minolta Scan Dual II since August and I love it. It's very easy to set up. I have had some small problems with the Minolta software, however, so you may consider checking out Vuescan which is a very flexible scanning program that supports it and a large number of other film scanners and flatbeds. It does a great job on negatives and is pretty close to matching what the Minolta software gives you for slides. If you check some older threads on scanning you will see Vuescan mentioned a few times. The Scan Dual II has some advantages over the original Scan Dual. It can batch scan (4 slides or 6 negatives in a row), has a higher Dmax (essentially meaning you can get more detail out of shadows and dark slides), and has a higher maximum resolution.
An excellent resource which helped me get the most out of my scanner is:
This is a great mailing list/discussion group devoted to film scanning. If you can subscribe to the digest rather than the individual e-mails since the volume is quite high.
Info on Vuescan is found at http://www.hamrick.com
The author of the program reads the filmscanners mailing list daily and is very responsive for technical support unlike Minolta