LG's approach is different to what most TV companies do.
Even their lowest end OLED range has all the
same bells and whistles as their high end. Except the 8K resolution of cos.
So what LG does is more of an aesthetic change and maybe a better speaker though it will be better to get your own dedicated speakers and it will blow any TV speakers out of the water.
So you can get their C model and you will get the same processor, picture quality, features and of cos, 4 HDMI 2.1 ports as their top end range.
The differences are, as mentioned, aesthetics. So CX is more for the typical stand on a TV cabinet or mount on a wall with a VESA mount.
GX stands for Gallery. So it is to be mounted and flushed to your wall like a photo frame.
And then the other range are rollable displays and maybe a better speaker. That's all.
There's also an entry level OLED. The B series. But that has low peak brightness. So I will not suggest that.
Both the C9 and CX has the same features. Same amount of brightness as well. So yes, after the current firmware update, the C9 has 120Hz BFI and all the bells and whistles. But at 120Hz and if you are gaming, VRR is better than using BFI.
Motion is instantaneous. In a 1000 frame high speed camera that records every frame in 1 second, it took only 3 frames. That is less than 1ms. And the visuals are crisp. That explains why even at 240Hz on my BenQ monitor, I still experience motion blur when playing FPS games even though it was supposed to be clearer with its ULMB (BFI)
This video at the
3m 52s mark tells you why.
I have an IPS and LCD panel for both my 2 monitors. And true enough, the OLED produces the sharpest (obviously with its 4K display) but also the most clearest at fast moving motion (as you can see how clear and detailed that alien fast moving test shows) even though the TV only goes up to 120Hz.
That video is even comparing to a better 360Hz monitor. So no amount of LCD TVs which includes QLED can beat that.