My experience is the same as gpflepsen (i.e. component output is OK, but S video is dark) but I don't think it was that way at the start. I got my unit on Dec. 12, with software 2.61, and at that time I think all the outputs were dark, although true HD material from the satellite (such as Discovery HD) wasn't too bad. But later the component output seems to have been corrected, while the S-video output is still dark. Someone else on one of the topics on this forum noticed this as well and posted about it, saying that either version 2.62 or 2.63 seemed to correct the component outputs. I can toggle between the two and definitely see a visible difference in the darkness of the picture between the component and the S-video. My current version is 2.63LABD-N (Bootstrap version 1010LABD).
Depending on what I am watching I may use one input or the other, so I do hope that they eventually get this fixed.