Where do you sit when watching TV?
I ask because I am currently in the process of returning my second F8500 due to buzz. Altogether, the TV is amazing, but I cannot stand the buzz anymore.
If you prefer to sit directly in the middle of the TV, then I assume you will experience the same buzz I do. It is loud and audible over any standard volume, because it seems to be a frequency that does not blend in with the rest of the audio.
The input lag was also quite noticeable. I am a gamer and have been playing GTAV on it. I have tried game mode, which did little but make the picture much worse. I also have renamed my HDMI input to PC, which definitely helped, but did not make it ideal.
Just my input. If you are sensitive to noises like the above, I would avoid the F8500. In the past I have noticed noise coming from PC power supplies, and other sorts of "electronic whine", which does not seem to bother about half of the people I ask.
Good luck with your decision, and I hope you don't get a buzzer!