I don't think that it is necessary to make contact after every single viewing, but he should at least be making contact to set up each viewing in which case you can ask how things have gone. Many people seem to want immediate feedback, but when you bought a house did you give feedback to the EA or did you think about your decision for a few days?. If you are not happy with the sales brochure, put together a list of amendments and send them to him and state if they are not changed you will have to look for another Ea.
TBH I would be very surprised if he was not trying as hard as possible to sell your home as it equates to 2 sales.