I use and recommend QT with IB. I use QT for charting, not for trading.
Medved, who owns and runs QT, provides an extremely high level of support for his product. He tells you how to use it, and he fixes bugs. QT is designed so flexibly that you can do all kinds of different things with it. Just recently, as just one example of how flexible it is, I wanted to make a chart in which the vertical axis would be price, but the horizontal axis would be cumulative daily volume (instead of time of day) - and sure enough, QT already had the features needed to do this.
P.S. Medved apparently doesn't sleep, at least it seems that way, when you see how quickly he responds to your emails. I think that the quality of support he provides is second to none in the industry.