I've been to the Windy City many times, and I still can't quite figure out what Chicago-style barbeque means. There are MANY Chicago transplants in the Sunny City, and I think this is just advertising, because it tastes like regular old barbeque to me, although a bit oversmoked in my opinion.
Tom's is near my house, so I have been there often, spoken to the owners, tried most things on their menu. I love the fact that they have side salads, which many BBQ places don't have. They said they tried creating a low-carb sauce, but people didn't like it, and it spoiled before it was used up.
Now that there are more choices in barbeque, I drive for my meals rather than revisit Tom's. These days, I think both Chicago Tom's and the Chicago Cubs are both overrated.