I am considering buying a floor model of a Samsung LN46A550. I know its been powered on for many months for about 12 hours a day (probably on high contrast settings). Is there anything i should know before buying it? Even if it was on for 1 year straight at 12 hours a day, thats only 4000 hours, and these tvs last 100,000. Do LCD tvs PQ start to go down with use, or is it a matter of it either works or doesn't?