I got a "replacement" sent from Amazon today, but I rejected it... here is my current 3-star Amazon.com review for the 60PK550 with more details:
I've decided to try to exchange mine. There are two big issues:
* It buzzes loud enough to hear at my normal listening position. I haven't read many complaints about this so I assume this isn't normal. UPDATE: Tightening the back screws helped reduce the buzz.
* There's a piece of lint under the glass that is annoying and distracting (see photo I uploaded). Can't really see from normal viewing position, but combined with issue #1, I'm not happy.
* Relatively inexpensive for a 60" TV
* Does have some great picture quality, but unfortunately black level doesn't seem to be as good as my older Pioneer 5080HD, but it's still pretty good when the brightness is adjusted down a bit
* Proper viewing/processing of 24P material like Blu-ray movies
* Relatively highly reflective screen - so windows or lights in the background could be a problem
* Questionable quality control
* My TV was manufactured in Feb 2010, even though I received it in August, 2010
UPDATE on 2010-08-26:
* My replacement came today (thanks Amazon for great service - I highly recommend you buy from them).
* The new set (also manufactured in Feb 2010, even though I ordered in August, 2010) also had buzzing and had screen defects as well, in at least 3 places (I did a white wash to see them). I did not accept this set. It also made a popping noise while doing the white wash, which concerned me.
* I'm going to keep my old set. I later learned that I was able to significantly reduce the buzzing my tightening the screws in the back (which I learned from messages about this issue posted on the Internet). Unfortunately the LG tech didn't know about the "screw tightening trick" and just said the buzzing was normal, but when I heard the buzzing while watching TV from my normal viewing position about 12.5 feet away, I decided that amount of buzzing couldn't be normal. I've since reduced the buzzing by tightening the screws. The buzzing is still there, but it's not so bad anymore.
I'm sticking with my 3 star rating because of the quality control issues with this set, the buzzing, and the highly reflective screen, but it can produce some great picture quality.