Well I gave up trying to use the DPR search feature and read through previous posts directly. My impression is that surely all that can be said has been said except for specific comments on individual challenges.
So far as improvements to the challenges it is apparent there is no consensus whatever. Even if DPR had the resources I can see that they would be reluctant to make any changes for fear of aggravating more people than they would please.
Speaking for myself, I figure if I am going to play I have to play the cards I'm dealt and that's fine. The challenges are fun and I get to see some terrific photos in specific catagories. If I see that a photo of mine is a victim of biased voters, or heaven forbid cheaters, I will simply remove it. For example, I think my entry in the Ansel Adams challenge probably received significant low votes because it was not a B&W photo even though color was allowed.
Thanks to all the work put in by all the voters who approach the voting with an open and objective mind, and RaptorUK thanks to you and the others who have assumed an activist role in trying to make things better.