It's pretty simple: In order to tell the difference with blacks between the ZT60 and the F8500, you'd have to turn off all the lights or use a measuring device for the blacks. Even then, the difference is minimal. On the other hand, the F8500 is much brighter with much higher contrast that can be SEEN with the naked eyes, in any lighting condition. Add in better 3D, better Smart Apps, better Allshare video streaming (pretty much every codec is compatible), quad core CPU, and future proof with HVEC (.265) support for clearer and smaller streaming videos, it's a no brainer to me.
Why is blacks > brightness, whites, and contrast? To me, it's way low on the list as I'd rather have white whites along with extremely good blacks and high contrast..