I can tell you my personal experience with this adapter.
I have RTX 2080 Ti SLI, last week I bought LG 48CX and this Friday I received adapter. While I couldn’t get above 4K@120Hz 4:2:0 with adapter with the newest GPU driver (that you can already get with Turing GPU & 2020 model OLED), and with my 3D gaming driver 425.31 I managed to get to only 4K@120Hz 4:2:2 8bpc, I couldn’t get proclaimed RGB Full, or even 10bpc with 120Hz.
It took me A LOT of searching on internet to find out that drivers beyound 456.71 don’t work with adapter.
But after I installed working driver (456.71) I am very happy with adapter. I have working 4K@120Hz RGB Full 10bpc on my LG 48CX, and I have no dropouts/blackscreen. I can ALT-Tab from game to desktop, vice versa, and it works. I received dropout after having turned on PC for a whole evening, and turning on TV on lunch (Incorrect format on TV), but that is in my opinion acceptable :D. I didn’t receive dropout after 2 hours of turned off TV and turned on PC.
There is only one issue that I have, and it’s that I don’t receive proper colour space above 4:2:0 in 4K@120Hz 10bpc HDR. In 4:2:0 I get BT.2020, but above that (4:2:2, or RGB Limited/Full) I get washed-up colours in Windows or in game and NO_DATA when I look at HDMI Diagnostics on TV. Fortunately I can force proper colour space (BT.2020) in HDMI Signalling Override on TV. But I wouldn’t mind if they fixed it in following firmware update.
In the end with my limited experience I can say I am very hapy with adapter. There probably were many issues with early versions of adapter, TV firmwares and GPU drivers, but for me it is only choice how to maximize picture quality with my PC. Nvidia just need to get their sh*t together, because their recent drivers are mess, not just adapter issues, but many other things, like VR, shuttering, lowered perfomance, Chrome, LG OLED TVs not being recognized as G-Sync Compatible, even though it is supposed to ‘solved’, etc.