To me it's actually faster and easier to read code instead. This is because i generally don't trust "what" comments - either I know the code already or I don't, and if I don't, then I don't trust the "what" comment fully, so I both have to parse "what" and code.

A "why" comment usually ages well, so I generally trust it and can use it to better parse the code and its intentions.

So I belong in the "what only for API methods" camp.