Frank the Yank said:
Frank - He's had fall outs with one or two of his playing colleagues, and people at the club when he was a director. Tueart and Rodney Marsh famously didn't get on (even last week, Marsh tweeted that, "If Dennis Tueart said good morning, I'd go outside and check the weather!"). And in his time as a director of City, he made enemies of Franny Lee (who reportedly made it a condition of selling his shares to Thaksin that Thaksin wouldn't keep Tueart on the board) and Joe Royle (who was upset with the manner of his sacking).
He's a pretty self-confident guy who doesn't back down when he thinks he's in the right, so he can certainly rub people up the wrong way. Having said that, I've seen him at a couple of fans forums, where he was willing to stay answering questions and signing autographs for a long time, so based on that, his attitude to the supporters seemed to be spot on. That seems to be borne out, as well, by what some of the people on this thread have been saying.
Anyway, most important thing for me is what a great player he was. Doesn't get the recognition he deserved outside Manchester and Wearside. Went to Cosmos at his peak so I'm not surprised you became a big fan. As someone says, when he came back to Maine Road after two years, there was a fantastic atmosphere for his comeback game against Bolton. He scored twice, as well (though City managed to blow it and draw 2-2). Best memories are from his first spell, though.