Well, on the two sets (EX723 46" versions) that I have had recently, the "Eco" setting dims the picture considerably. So much so, in fact, for an LCD, it's impossible to watch. I should think this, coupled with the backlight on "4" would be impossible to watch on my set! As I previously mentioned in posts on page 1 of this thread, I find the blacks to be "very black" or "too black" on this particular set, so I don't have a problem with this on mine.... thing is, the picutre on darker scenes seems to auto dim (not so that you notice the fluctuation but as I say, blacks seems too black) and ruins the picture on darker scenes. My retailer is coming back on Wednesday to have a look as I now find the need to turn the brightness up to 60-ish which means I see the excessive clouding on the left hand side of the screen. No win situation for me at the moment!