To be clear, you’re still to perceive the vast majority of OLED benefits with that etched (semi-matte) layer atop the panel. It’s not as though the color vibrancy and absolute contrast are entirely lost once you go etched. The only downside will be that, during travels where you have strong overhead lighting, it’ll wash out some aspects of OLED. With that said, once you’re indoors and, ideally, in not-so-absolutely-bright ambient lighting, OLED will really come to life.

For anyone that owns an OLED TV (always glossy) and an OLED monitor (often matte/anti-reflective), this choice in configurations from Valve was a very, very strange one. With OLED being the primary, visual upgrade for the new Steam Deck OLED, you want to retain as much true black and color vibrancy as possible, and in no uncertain terms, any anti-reflective/matte coating will cause an appreciable hit to both.

As shown here by Dave2D, the 1TB configurations will suffer, visually, as a result of the etched display.

If you live with OLED on a day-to-day basis, you know that sacrificing color saturation and the absolute contrast ratio is a price not worth paying.