I've seen lots of posts on this tv so I took the plunge and bought one last week. It's arriving today. I did have 2 questions though: 1. What's the longest time anyone's had this tv on or is there a recommeneded shut down/cool off after say 15 hours? 2. Is there a need to calibrate these LCD RPTVS? I know it was a big thing with CRTs but haven't heard too much regarding the new technology.