I can't answer as far as difference between 2016 and earlier years because my 2016 is the only F6B I've owned. I can say there is no drone under any conditions I've experienced on my bike. Not at low speeds, not during high speed super slab riding.
I'd also say they seem to be a little louder and better sounding now at 9000+ miles than when I bought the bike new this past January.
It's still a little quieter than I'd like though. This past summer I had two cages try to pull into my lane right on top of me while going through the Chicago area and keeping up with traffic at around 85-90 MPH. Would not have happened on my old Valk because they would have heard me.