I just received my Fiio UTWS5 from local distributor today, old version tho. Upgraded to v1.42 fw and using it with Xiaomi 12S Ultra supports both aptX Adaptive (the phone will show Snapdragon Sound logo) and LHDC. Its nice, but encounter this one weird bug when UTWS5 gone crazy and output random interference noise at loud volume when I randomly tapped the right hook button to try play/pause. Restart the earhook and dont have that anymore yet. But keep that in mind in case you encounter it
Also one more thing to keep in mind: default aptX Adaptive setting will be 48KHz 24bit. You can try to change it to 96Khz 24bit to get a lil bit more sound quality, if you have a phone that supports it (Snapdragon 888 and up). Working fine in that mode.
With LHDC, like other reports before me it can only run at 500/560Kbps, no 900Kbps.
Some technical question to
@FiiO : Can you tell us what bitrate of aptX Adaptive codec the UTWS5 is using? Is it 420Kbps or 860Kbps? Do you plan to upgrade it to aptX Lossless (~1Mbps) in the future?
Also I would love to be a beta firmware tester if you want.