SMO: those settings are definitely the Day settings from Buzz. Maybe the Night settings would be better in your environment. I usually leave some bias lighting on at night (at my wife's insistence
) so the room isn't pitch black. When I do turn off the lights I agree that the picture can be a little too bright at times with the Day settings.
Clouding vs flashlightng: clouding is indeed random, anywhere on the screen type stuff. Flashlightng starts at the edge, usually in the corners, and spreads from there. You can sometimes rub out clouding but typically not flashlighting. That said, some have tried loosening screws behind corners to relieve pressure in an attempt to reduce flashlighting. I did that last night in the lower left on my set. Of course my mind thinks it made a difference but who knows?
6400 v 8000 and the $3400 difference: here in the US it's actually an even bigger price differential - $4000 (!) which means you could buy two (!!) 75" 6400s for the price of one 8000. Yikes. Marty it sucks that there is no 7100 down under (I wonder if you could import one somehow...) but IMO it wasn't worth the $1500 difference to step up to the 7100, so it's definitely not worth it (to me!) to pay an even higher difference to get to the 8000.
That said, I only compared the 46" 6400 to the 7100, not to the 8000. So I can't say whether or not the 8000 is that much better where it might justify the greater price premium. My understanding is that the primary differences once you get from 7100 to 8000 have to do with lighting trickery with ridiculous fake refresh rates and the like. And perhaps "even better" local dimming capability than the 7100.
Don't get me wrong - there was definitely an improvement to the black levels in the black bars on 2.35:1 content when comparing the 6400 to the 7100. It simply wasn't a $1500 difference for my eyes or wallet.
Marty maybe there is a shop you can visit to compare them side by side at a smaller size, and then decide whether the difference is worthwhile for you..?