Thanks for this info. So it appears that my use case requirements can work then. I'm replacing a setup where there is a ethernet cable between 2 routers with the 2 new mesh units and the third one goes into an annex but I am not sure if the wifi coverage will reach it so the PLC capability should help. The old setup is super old so I think the wifi coverage will be improved even with just 1 node

  @Philbert 

I have several PG2400P powerline kits around my house and they work very well. Having just taken delivery of the Deco PX50 I can confirm that despite them both using the G.hn powerline standard they do not talk to each other and these does not seem to be a way to create a single powerline network using the two systems.

I can also confirm that the two systems interfere with each other terribly, so much so that my PG2400P network becomes unusable with the Deco PX50 system installed. I have had to remove my Deco PX50 units and will be returning them.

The powerline feature on my PX50 mesh doesn't work, it only connects via WIFI no matter where I plug in or place the units even on the same outlet they only connect via wifi.