My P55-gt50 arrived saturday and I have nothing but great things to report so far. I have not seen any IR. I hear no buzz even 2 Inches from set with audio off. I have the contrast and brightnessdown to 50. and honestly its plenty bright in my settings picture looks great. we did watch a movie in THX mode, not much differeance. I am avoiding black bars at this point during break in and have only seen a few commercials and tested a few blu-rays that were widescreen maybe for 10 minutes. seen plenty of logos, MBC olympics, golf, football game tags, and can not see any retention. having no issues, great TV.
my take is baby it for a few weeks, or 100 hours.