It is usually one or the other. On relatively normal filings the written response is the way to go...when you want to.. make your point ..esp. when one has to ...convince...the person rejecting your claims, the face to face request is the fastest and most influential way to go. CM being there, like the last time, is a good thing...but IMO...having the right lawyer there,esp. someone who has gone through this with the PTO before is of the most importance...and of course if that is done no need to have a written repsonse. When the meeting is concluded the examiner will post who attended, on what date, and what was disussed in the meeting.