I don't object to dissenting opinion. What I object to is people who say the theory is wrong because of something that is not part of my theory.
For example "I was hit by Penguin, that proves your theory is completely baseless".
It's a nonsense objection. Reasonable objections I can handle.
The user metric discussion is the heart of the idea and I agree it's the really interesting part for various reasons.
I conducted an experiment earlier this week which may be of interest. I removed two high exit rate products from a category page NOT affected by Panda because I recall the rankings of this page drop when we added them a couple of months ago. The page has been ranking 8th for the past month, no fluctuation. Today it is 7th. No SEO activity going on for that page. Could be due to some other ranking factor improving as a result but I wonder if it's because I just improved the user experience by removing those two high exit rate pages.