In my office I have a ceiling fan (not sure what brand) with a light and I have 2 - XPDI3 switches zip tied to the frame under the shroud. I (luckily) am not getting ANY buzz from the ceiling fan either at full brightness, or dimmed. I do realize that this is a fluke, as most ceiling fans controlled by an XPDI3 have serious or at least some buzz. The ceiling fan in my living room also has an XPDI3 and has a slight tolerable buzz when dimmed. Most times when we are in there, we are watching TV so the buzz gets drowned out by the sound of the TV. Both rooms are controlled by wall mounted XPT switches.
I still plan to add this feature to our master and guest bedrooms and our dining room. It would be nice though to have an all in one unit designed for a ceiling fan fixture. Possibly 2 styles, one for fan only, and the other for fans with lights.