Removing spam can be done in a number of ways, including the removal of self upvoting, and the value of posts could be improved with more accurate cheetahs that catch more real copies and worry less about recurring theme posts like contests, that always get a cheetah label slapped on them for the author using his own content.

More cheetahs, better cheetahs, remove self voting, and a LOT of the noise would go away. Not all, but a good bit, in my opinion.