In reply to Danny Brown.

The benefits we’re most interested in are speed and reliability. Previous to REST most apps or services which interacted with WordPress did so over the ancient and insecure XML-RPC or would write their own API to hit admin-ajax.php.

The former just isn’t reliable or secure. The later isn’t performant because it load WordPress each time you hit it.

As far as day-to-day from the user end of things you can expect to see faster comment loading in Epoch, as well as a much smaller overall plugin footprint as it won’t be adding our own custom API…