I posted a critique of your novel. Another good reason for posting on Rorshachs is that when someone posts a response there, your initial posting springs to the top. That way it doesn't get buried.
If people never see your postings because others have buried it beneath theirs, then its harder to get responses. But if you are on Rorshachs, since people post there less AND responses push you back to the front, other people are more likely to see your stuff and comment upon it.