I have a C6, which is very similar but I think it is a higher resolution (600dpi). I thought the quality of the scans were fine, but a hinge on the cover snapped off after a few months of light use. Then about a couple of months ago it started acting very strange. The drive motor would kick on and make a loud buzzing noise, and my computer would lock up. It finally got so frequent that I had to disconnect it. I'm in the market for a new scanner now. All that after a little over two years.
Hope you have better luck.