The audio is through a singular source; no mixing jarbled mess. It would be awesome to have some kind of sound channel mixing, but again... it's 2021 and we don't have an easy way to PiP yet (lol).
I've noticed a couple differences between the faulty box and this OREI box.
PROs (for the OREI model)
- Each windows source can be changed to a different source. [All 4 windows can be HDMI 1 if you prefer]. You don't have to change HDMI cables to move pictures on the screen.
- Remote is not a Chinesium LED remote that breaks in 2 hours. Though, not entirely a fan of the 2025 battery.
- Has been working for more than a day now without issues
- Seems to have better airflow / venting.
- You can power the unit down.
CONs (against the OREI model)
- There is no indication on what Audio source you are on (faulty box had a music note next to the active channel).
RESO on the device/remote changes the resolution from 1080p to 720p (and back). No real benefit for me.
Other than that, I just got this and haven't had any complaints really. Other than the price, because again, it's 2021 guys, why is this not a feature already.

*Side note*
Some TVs do have PiP, where you can view 1x HDMI and 1x COAX at the same time. My old school Samsung from 2005 did this. It seems I must have been spoiled at the time. Results show that Samsung has continued PiP with multiple HDMI, but I'd rather wait for the price of Samsung's 65" TVs to go down in price / improve for the cost while I sheepishly use a crappy Hisense for the time being.