It’s just a matter of bandwidth, and signal strength. Each person’s setup is completely up to them, and neither setup is better or worse for all use cases. You should use the one that suits your situation best. The rest of us will be pleased there are multiple options. 

If your home WiFi is sufficient to stem your Sonos system why did you get a Boost in the first place? I’d never run Sonos over WiFi but that is just me.

Multiple reasons: many consumer WiFi routers suck, especially when there are a lot of devices communicating with each other (instead of the “easy” case of communicating with the internet); other devices use your WiFi, increasing the chances of you Sonos data getting delayed or messed up (causing glitches); WiFi only good for a small number of devices -a  decent sized Sonos network should always use a BOOST, esp as then every player is a SonosNet repeater too, improving coverage.

WiFi should only be used on simple setups IMHO, I have a two-speaker system that does fine. However my larger systems are SonosNet all the way.

I think the bigger question, “Is the implementation associated with the new Move speaker the start of phasing out the Boost/Sonos Net?  Five years ago WiFi was pretty poor, today with Tri-Band, mesh networks, greatly enhanced coverage (beam forming), etc., I wonder if the Sonos Net is on the wrong side of the performance curve.  I just don’t understand why the Move speaker only connects to WiFi (+ Bluetooth) and didn’t even provide an option to connect to SonosNet.  When 5G techniques are implemented into WiFi, even Ethernet (wired) is going to be phased out because it will be easily outperformed by 5G schemes.  Who would have thought?

I believe the reason two portable Sonos devices don’t support SonosNet is because they should never be chosen as a Coordinator device (in a Group), as they can vanish unexpectedly. Keeping them off SonosNet will achieve that.

Portable devices can be GC. In the case of a single player it has to be GC. 

The cited reason for not being a SonosNet participant is that as the portable moves around, the mesh topology would keep having to be recalculated. Also, if the portable was functioning as a relay a dependant node could drop.

Sounds reasonable but begs the question why do I get a warning saying ‘a device is connected to a WiFi network and can’t be used in a grouping’ when everything works fine?  Do I just ignore the error/warning message. My WifFi coverage greatly exceeds the SonosNet coverage.

The Move must have attached itself to either an extender, or a satellite on one of the WiFi meshes which appear to Sonos to be extenders.

You may be able to ignore it, but in some cases a group member may fall silent.

Thanks for the input.  Having talked to Sonos a while back, I think Sonos goes 3-sigma high when they see an extender in the WiFi system.  I do have an Netgear Nighthawk extender in the system but it is 300 feet from the Move whereas the WiFi router is 20 feet from the Move under most situations.  When I was talking to Sonos the first thing they wanted me to do was remove (turn off) the extender even though no Sonos equipment was connected to it.  In my previous WiFi system nothing at the far end of the house was able to connect to the AP so I put an extender in the system.  About a year ago I upgraded to a Netgear R9000 with an EX8000 extender based on previous connectivity experience.  Turns out that technology had advanced so much (beam forming), I found that everything would connect directly to the WfFi router (AP) without the need for the extender. With the old system part of my HfFi system would connect to my neighbors open WiFi system since it had trouble connecting to my AP.  I initially missed that this had happened since my neighbor’s SSID was Netgear and since I was running Netgear, the connection went unnoticed since my SSID was similar (XXX_Netgear).  When I went thru the expert connection method where I cited the equipment’s MAC - it would never connect so I eventually executed the dummy (automatic) connection technique and it connected immediately which turned out to be my neighbor’s WiFi system.  I immediately asked my grad school for a rebate on my EE degree. PS -  my neighbor finally put a password on his system when I told him I was using his Internet!!