You tryed that in particular?
Or you think all converters like that are crap? If you read the manufacturer web page, looks like its a good option.
I once tried the Aver TV Box9, but returned it after looking at the mediocre image quality. Composite looked really blurry of course and things improved only a little bit when I used the s-video input (connected via genlock).
There is nothing wrong with these devices, it's just a basic difference in signal standards. When using anything other than RGB or Component, the signal quality is severely degraded. I spend a bit more and bought the CYP CM345S which accepts RGB through SCART connectors as input.