Thanks for the response Ken, you are of course absolutely right on both points – though I would argue that the volume of data that a machine could analyse in an instant is an order of magnitude more than a human (and sometimes quantity over quality will be important).
I think your last point is very interesting and likely the key thing that those who run chatbots will need to crack in order to make them a success. I think there should (and will) be a different set of expectations set for conversations that humans have with machines – empathy will not be expected, but efficiency, speed, accuracy and honesty (above and beyond a human) will.
I believe that in many situations the majority of customers will gravitate towards more efficient machines, but they will be held to higher standards. The first bot programmed to lie or mislead could have serious consequences!