I am trying to decide on a TV... and narrowed it to 2 28PW6518/05 or 28PW6520/05 i can find lost of info on the 6518 model but not the 6520 model. Picture quality is the most inportant thing as all sound will run through a amp. i really like the picture on the 6518 and was already to buy it but then stumbled on the 6520 model (is this a updated version of the 6518???) both TV's are about the same price online. your opions would be gratefully recived.