A few years back I needed to set up in-home wireless audio streaming for a friend’s home theater setup and I dove into a ton of this nonsense with audio codecs, latency, etc, etc. It’s not something you hear a lot about so I’m not surprised virtually no reviewers even mentioned this new Steam Deck OLED feature, but AptX-LL is a godsend for high quality low latency audio - as low as 30ms, compared to 80-300ms for other common codecs. The sound quality’s excellent too.
The only problem is, not a ton of headphones support AptX-LL. It’s become an almost deprecated format because it requires a compatible transmitter and this probably costs phone companies an extra $0.01 or something. Barely any devices take advantage of this technology. If you’re lucky you might find something supporting AptX-HD or Adaptive, but not LL.
Fortunately Valve added AptX-LL support to the Steam Deck OLED, and there’s a pretty good pair of headphones available (relative to the price anyway): https://www.amazon.ca/dp/B08QRQMLVY (“Sound Blaster JAM V2”, and not a referral link)
I ordered a pair a few days back and they’ve been terrific! They’re no match for the Sennheisers on my desktop PC but they’re surprisingly decent. A nice upgrade from the Deck’s built-in audio, and you don’t have to dick around with a cable. Plus if you have audio buzz, these completely bypass that issue. If you’re familiar with how shitty Bluetooth audio becomes when you have a wireless headset’s microphone active, these avoid that problem too because by default you’ll use the Deck’s built-in microphone and the headphones only for audio output.
Unfortunately these headphones do have one issue you’ll commonly find in older or inexpensive USB-C devices though: they must be charged using a USB-A to USB-C cable. A direct USB-C to USB-C cable, or a native USB-C charger like Steam Deck uses, probably won’t charge them. They do claim to have 20+ hour battery life though, so at least it won’t be a frequent annoyance.