The author holds up Wikipedia as a good example, but I have found the wikipedia experience on my phone to by abysmal because the back button doesn't behave correctly.

When nagivating to a Wikipedia page I get a flash of the normal page then a redirect to the mobile version. Pressing back gives me the normal page which redirects me forward. to actually get "back" I need to double tap quickly enough to actually escape the site.

Many other sites do the same thing but Wikipedia stands out in my mind as consistently frustrating.