I bought a Kuro 5020FD a little over a year ago after doing research on these forums. I've heard Pioneer isn't making displays anymore, so not sure how valuable this info is, but here are a couple things I noticed:
I do have the issue with a slight buzzing noise which some people have mentioned, but it is very minor and all other sounds have to be off to hear it. It doesn't go away while the TV is muted, but really it's nothing to worry about. I never got surround sound hooked up so I'm still using the speaker that came with the TV, I wonder if the bass from the speaker rattles it a bit. It's really not a problem at all, you can barely hear it.
Overall it seems like it is designed to be in high-end entertainment systems and not an average consumer's living room. For example, I can't seem to find an option to display black bars in 4:3, I think there is only gray and gray that adapts to the colors of the screen.
Y ou also can't change the input for about 20 seconds after turning the TV on, which can be annoying if you're trying to set something up then walk in the other room. The good news is, you can watch anything you want without any burn-in problems, I am guessing this is a thing of the past. I did the "break-in" DVD for about 4 hours the first day but I've never had a problem with burn-in.
The pictures is still good enough to make everyone else jealous, though, and I'm super happy with it. So there is a really late review from an average joe.