Encyclopaedia Brittanica rejects Nature’s evaluation of Wikipedia and Brittanica

I posted on the original study, so I figure I have to post on the follow-up: BBC NEWS | Technology | Wikipedia study ‘fatally flawed’.
Encyclopaedia Brittanica has posted a rejection of Nature’s evaluation of Brittanica and Wikipedia, calling for a retraction of the original article. Nature has rejected Brittanica’s rejection and says that they will not retract.
And I ask, but which one is more of a knowledge development tool? (Hint: I think transparency is necessary for the knowledge development process.) Evaluating something like Wikipedia based solely on content sort of misses the point, in my view.