I actually just returned my F8000 for the Sony w900a (non 4k) a couple days ago and am happy with the change. I absolutely loved the Samsung but the lag on mine was terrible even after the latest updates. I also was experiencing a lot of motion blur and couldn't get it the settings right to make me happy. I have no idea how everyone on this thread feels the lag is fixed, maybe i was doing something wrong (also tried directly connecting the Xbox to the tv).
The Sony lag time is great, colors are amazing, still getting the black levels set right, and the viewing angle seems better than the F8000. I really wanted to keep the Samsung but i was also noticing a lot of issues with HDMI connections not working 100% right as well. Black screens, settings were thrown off, random sound outages, maybe i got a dud or one that was turning into a dud.
I am not posting this to say anything bad about Samsung, i am just disappointed that Samsung seems like there quality control is in question...yes i know they sell alot but thats not an excuse. Sony was not my first choice but i am not disappointed with it at all. I was interested in 4k but decided to wait a year to see what the models will bring, so this sony seemed like the logical choice to get the best PQ, lag time and black levels all in one package.
i really do appreciate everyone's help on this forum, its nice to know there is a solid community to get great information and help when ever you need,
Sony w900a would have been my first choice no doubt ( I am a Sony loyal customer, I have to admit), but because it wasn't available where I live, I got the f8000 instead for the time being, I had the Sony HX850 not so long ago, but had to return it after I discovered it was used for about (2000+ hours). it is a pity, but you live & learn, I can say it now Samsung f8000 is inferior to Sony's the 2012 hx850, the colors & black levels were Amazing! on the Sony, really amazing., Thanks