Right now, it's between the LG 27GR95QE-B and Asus PG27AQDM if you want a 27" flat panel. Ultimately, both are good options and any OLED is fantastic for colors, as you know.
But hear me out, consider the Alienware AW3423DW or the MSI Meg 342C instead. The Samsung Odyssey OLED G8 is an option as well if you're fine with a sharper curve. While all of these are 34" UWs, the image quality is unmatched with a QD-OLED panel and compared to the W-OLED LG produces for its own monitors and for other brands.
Note, we tested the LG model in-house and didn't have any brightness concerns that gamers online have consistently noted, including here. The shipped models improved upon some of the brightness issues LG had in early demo's.
But regardless, the alternative models listed are far brighter and punchier than any OLED, including the PG27AQDM. We compared the LG OLED next to both the Alienware AW3423DW and Samsung Odyssey OLED G8. From firsthand experience, there is a noticeably better image quality with the Alienware and Samsung monitors.
While we haven't done the same with side-by-side comparisons for the PG27AQDM, the picture quality improvements over the LG model will be minor. Both use the same LG-built W-OLED panel, so they're practically the same, with the Asus enable to squeeze out a few more nits in select scenarios. Then the only real differences are aesthetics and HDMI 2.0 vs 2.1.
I wrote a detailed OLED gaming monitor buying guide comparing the top picks and I've included it below if it's helpful.
https://www.setup.gg/reviews/monitor/best-oled-gaming/
I'm also happy to answer any questions you may have. Just shoot. I've tested the following OLED's firsthand: LG 27GR95QE-B, LG45GR95QE-B, Samsung Odyssey OLED G8, Asus PG42UQ, Asus PG48UQ, and Alienware AW3423DW.