Why am I telling you this? Because the one you're interested in may lack that feature as well so make sure you check if having dynamic tone mapping matters to you.
i can tell you first hand the C2 had better image quality.
No doubt... but the 48gq900 has i think better burn in protection.
I had the odyssey ark for 3 days total before i returned it.
It had bad pixels, and it weight'd 100lbs.
Also i did confirm no one sane should have a 55inch monitor less then 3 feet viewable unless you want neck and back problems.
But my intital take...
Nano-IPS has the best colors and fastest panel for the colors accuracy, horrible light bleeding.
OLED has the best blacks, and things look super fruity on them... like if u see an apple on it, you really want to bite into it as it just looks so delicious.
FALD QLED MiniLED... aka the Ark... i think is a mix of both, its not the best in both, but it takes as much as it can from both and blends it to the best of its abilities. It also had the best HDR, if you saw the image of the sun, you had to wear sunglasses as it was that bright, but again in the apple reference... it wasn't as delicious looking as the OLED, but looked crisper then the Nano-IPS.
phew i went though so many monitors this black friday / cyber monday, im tired as heck.
Also the UPS store would look at me funny, as i returned a C2, and a Ark, and they were like i guess the third one's the charm? which i smiled yup, its the LG OLED Monitor and not TV.