Got the Emotiva CMX-2 yesterday (thank you, Emil!).
Upon initial install early yesterday afternoon, no buzzing from the Uber to be heard. Of course, the worst buzzing always happened in the evening so last night, maybe around 11pm, I cut the music off and got down within a foot of the UberBuss. Yes, could faintly hear a slight buzzing, but nothing like it had been. So, whatever the CMX-2 is doing, it seems to be working to large extent and definitely worth the price of admission.
I will say that I was a bit concerned that the addition of the Emotiva would somehow affect sound quality (although it claims no current limiting). Well, after maybe 3 hours listening last night and another couple this morning, I couldn't discern any negative effect from it. I'll give it a few more days to acclimate (it and me), but for now I'm calling it a qualified success.