I was visiting Circuit City the other day...eyeing the PT53WX42, and the salesperson suggested that because we live in Arizona that we get much more dust in our homes. This dust gets in the grooves of the unprotected screen and is very hard to clean. He further suggested that this, over time would harm my viewing experience and for another $200 they could install a protective screen for me. Any comments on cleaning a PT53WX42 screen? Thanx!