There is a great deal that could and should be written on this topic. It would be nice if somebody would rewrite the whole article so that it does actually inform the reader about the main goals and achievements of the 1989 Convention. If I have to do it, I will have to get my hands on some back numbers of JIPA, as various papers related to the Convention appeared (before it and after it) in that journal. I remember co-authoring a paper with Peter Ladefoged (he was IPA President at the time, and I was Secretary) which was meant to be a sort of tour d'horizon to help define issues that needed to be covered at Kiel; we produced the first draft of the paper when I was visiting UCLA.
There was a group photo of all the people who attended (I still have my copy), and I think it was John Wells who recently put a copy of this on Facebook to see how many names could be recalled.
I remember it being a pleasant occasion, with a businesslike atmosphere (and an enjoyable banquet). I travelled to Kiel in our campervan, taking 15-year-old Matt and his friend, who stayed on a campsite while I stayed at the conference hotel. I cycled out to the campsite twice a day to check they were all right, and this was the first time I had cycled on purpose-built cycle ways. It was a wonderful experience to ride along the car-free roads, noticing how friendly the cyclists were to each other. The high point was when some helpful riders showed me to the tiny free ferry taking pedestrians and bikes across the Kiel canal.
There were phoneticians there who didn't seem to belong to the usual crowd that one met at phonetics conferences. These were people who were usually engaged in fieldwork on little-known languages far from Europe, and their views were given a lot of weight; many people, including me, were dismayed at the changes to the symbolization of clicks and of tones that were the result of their input in the special sessions.