The Digital ICE, which is the hardware-based dust and scratch removal works really well.
The ROC color correction helps in extremely old slides and especially with negatives. The color quality of the images is thereby partially bearable. But Beware! Sometimes it is helpful to disable ROC and to see if maybe the colors are better reproduced without ROC. Unfortunately, the software is a certain "life of its own", so that the results are not always predictable.
The GEM sharpness correction is to reduce the grain, but I could not really notice.
At some point you have found the correct settings, and can look forward to long-lost photo Treasures and discovers his old favorite photos back.
The quality of the scans is convincing for me. I scan by default with 3600x3600 dpi then what a picture as to the 12 Megapixel results. In my experience, a KB-negative or -Dia are also here no longer, so that 7200 DPI actually just wasting space.
Miracles should not be expected - or perhaps.
The quality of the scan depends namely also on the analog camera and the film. If I have taken in the past prefer images with the cheap no-name movie with the revue Insamatic, I must not be surprised if the scans are not so super. But in some old slides (40 years and older) I was happy insane what all there is to see!
In conclusion I can say that the results are worth the Crystal Scan the high time involved. It's just a hobby and fun. Once the images have been edited yet something is obtained really great results that do not need to fear comparison with digital images.
Addendum September 2014:
I still scan with the unit, as has so far still nothing better on the market. What's really bothering with prolonged use that before the dust before the appearance of the scanner sets (long vertical stripes on the scan). Since it is advisable to have at hand the vacuum cleaner and suck the device thoroughly. Then all is well again.