I use MDN as much as I can, and will pick a page from it even if it is lower in search results. I don't know how page ranks can put something over an MDN page.

Long ago when I first started seeing MDN references, I had assumed the M = Microsoft. That meant I avoided it like the plague not wanting to see IE specific or .NET type cruft. Boy did I feel dumb when I finally learned that's not what the M stood for and realized I could have been using it even earlier. Yet another example proving you know what happens when you assume