What he did well was renovate the city in a way that has gotten near universal approval from all quarters. Downtown Providence is a tastefully rejuvinated area that simply works very well both for business and public/social coniderations.
I was wrong that he went to jail twice, only once. He resigned as mayor twice. The first resignation as mayor was required after he pleaded guilty to attacking a contractor with a lit cigarette, an ash tray and a fireplace log (what ever happened to brass knuckles and switch blades?). He accused the contractor of having an affair with his wife. Ciani himself had promoted the law that ended up forcing him to resign. He was later reelected as mayor and it was during that tenure that the feds charged him with about thirty offenses related to bribery etc but actually nailed him only on one racketeering charge. He was in the federal pen for about five years. Got out a few years ago and threatened to run for congress but so far hasn't reentered politics. Google Buddy Cianci and you'll find books and even an award winning documentary about him. His biography, which has a great title, is: Politics and Pasta: How I Prosecuted Mobsters, Rebuilt a Dying City, Advised a President, Dined with Sinatra, Spent Five Years in a Federally Funded Gated Community, and Lived to Tell the Tale