I would agree. I loved my ZT, but it was too dim, even in a totally darkened environment. For 3D, it couldn't even push enough luminance to bring out detail. Consulted with two calibrators, both who told me that there wouldn't be too much they could do to push brightness.
So, based on that, I think you made the perfect choice. I am far happier with my F8500 than I was with the ZT.
I understand what you are talking about. The ZT has a more tamed, cinematic look to it. The F8500 looks more like video. It takes a little getting used to, but there's ways to perfect that picture. If you are getting a "soap opera" effect (where movies look like a stage play or tv soap opera) then you need to turn off Cinema Smooth. However, there is a "bug" that Samsung is aware of, and you will probably need to do the following:
There still is an occasional bug when you turn off CINEMA SMOOTH. It sometime puts MOTION JUTTER CONTROL in smooth, even though it says it is off. So immediately after turning CS off, turn MJC to smooth, and then back to off. Then you can watch all your 24p material without issues. You only need to do this once, unless you turn CS on again. For some weird reason, they have not fixed this bug with MJC.