One more networking data point:
Back in mid-November Emile suggested the Amplifi HD as a cost-effective device to set up a low-traffic connection between ISP-provided modem/router and the Extreme.
https://www.whatsbestforum.com/thre...treme-the-crème-de-la-crème.27433/post-755528
At that time the new OS configuration and USB drivers were only a twinkle in Emile's eye. Unfortunately, at that time time the Amplifi HD was out of stock and back-ordered at the Ubiquiti USA webstore as well as the other retailers I checked. Since Ubiquiti's price beat many of the other resellers I put one on order and after a couple of weeks promptly forgot about it.
Fast forward to yesterday, and what shows up on my doorstep but a shiny new Amplifi HD wifi router. So, since I had it in hand I decided I'd give it a try.
Setting up the Amplifi HD using their free app available at the Apple or Android stores was very easy. Literally in minutes I had an audio-only feed from ISP-provided modem/router > copper ethernet jumper > Amplifi HD > 50' copper ethernet > Extreme, broadcasting a wifi signal specific to that branch only.
Well, once again (is there any doubt by now?) Emile is right when he states that this kind of reserved branch circuit is no longer necessary with the improved OS settings for the Extreme. I didn't hear anything I could put my finger on as a sound-quality improvement using the Amplifi, nor did I hear any degraded sound-quality. I cycled through all the reliable and very familiar tracks I use to test system changes and they all sounded the same as they do with my previous network configuration:
ISP-provided modem/router > copper ethernet > cheap-ass™® unmanaged switch > 50' copper ethernet > Extreme
So, barring any new revelations tonight (none so far) the Amplifi HD will go back in the box until my StarLink internet service is delivered (some day, Elon, some day) and I discontinue my DSL internet service.
Note: Is it just me, or does it seem the height of irony to call 12mbps down/2mbps up DSL internet "service"?
Steve Z