Becoming an even bigger believer
I recently picked up a p60gt30. (See my other post) And it's been my main gaming display for now for a week just to try it out. I've had a C9 LG OLED since 2020. Before that I had a p42S2 that I sold when I got the OLED, so I was familiar with plasma.
To say I am impressed is an understatement! Wow! I might not go back to the OLED. Seriously. I do play the occasional big triple AAA game that has a good HDR implementation but even then... I dunno. For example, GOW Ragnarok. The HDR is supposed to be one of the best implementations of HDR available. It looked washed out for me on the OLED no matter the HDR calibration settings in the game that I tried. The plasma in SDR looks more natural. Even at 1080p and the larger screen size it somehow feels more like looking through a window into the game rather than looking at a screen. Secondly, the motion clarity. I just tried out Hades II, and wow, it was actually easier to track movement due to the motion clarity, and I normally play the game at 4k120 fps on the OLED and only 60 on the plasma. No HDR in that game so color space wise they're similar. There's also occasionally these moving effects when you grab a boon and the corresponding Greek god is talking, like leaves falling or snow falling. Again, this motion looks better on the plasma.
There are also a bunch of logistical downsides with running the 4k OLED:
you need a GPU capable of driving 4k120. 1080p 60 fps is literally 8 times less pixels generated. DLSS / FSR help this but it's still hard to achieve especially in the newest games. You can use the same GPU horsepower instead on other effects (ray tracing) or just save power.
If you have a home theater setup, you need janky workarounds to get low input lag + surround sound via HDMI OR shell out big cash on an expensive receiver that supports eARC and HDMI 2.1. My setup with the OLED has an HDMI port from the GPU going direct to the TV, then use a display port to HDMI converter (that supports audio) to connect to the receiver to provide surround aound. With 1080p it's just an old receiver you can buy second hand for less than $100 and just once connection for standard ARC. (GPU -> AVR -> TV)
Cheaper HDMI cables. Not a huge deal but still a requirement
HDR is janky. In windows it works fairly well in most games but you have to hope a game that enables HDR has a good implementation and good in-game calibration. Most times I don't really know what is a good spot and find my self going back and forth with those sliders. Obviously any game not relatively modern doesn't support HDR anyways.
As much hype as there is for Linux gaming now, HDMI 2.1 just isn't supported in Radeon drivers. There's also some janky issues when using Valve's game scope where it can't seem to accept surround sound or HDR????
The OLED isn't all bad of course it's an amazing TV in its own right. FFVII remake for example just doesn't look right with the plasma settings I have when every other game looks incredible. On the OLED the FFVII remake looks amazing in HDR. A colorful game like rocket League also looks great in HDR too. There's just so much more work required in taking full advantage of it when it's better in many technical specs, but in some key (somewhat overlooked) areas it's worse.