@Russ_G 

The mesh capabilities of the Deco only work among themselves.

The RE505X will work with the AX50, but you will not have OneMesh like you mentioned. So the RE505X will operate like any typical range extender. In not having OneMesh your devices will not jump to whichever network device seamlessly. When you move around, if your device then connects from one AP to another you might notice a drop in connection. You can still name your entire network to be one name, but without protocols existent in mesh network you may see issues. I would recommend having the network names different to avoid any confusion where you are connecting to.

The RE505X would probably be the better choice to since that can extend your current AX signal. You can still go with an AC extender like the RE450 if you are not worried about not extending the AX signal.

@Tony Thanks for the reply, Tony. You helped me understand the mesh concept. You wouldn't believe the inept responses I got from two sepearate phone calls to tech support, asking the same questions.  I've done some more research, and the mesh technology would appear to be the hot setup for extending WiFi throughout the house. I guess the major advantages are the ability to hand off the signal from one access point to another while roaming the house without having to manually switch access points, better handling of backhual trafiic and simple management. Makes sense to me. The part that doesn't make sense is why a new, upper-end router like the AX50 doesn't support mesh. The AX20 does, an otherwise lesser router than the AX50. Had I known what I know now when I bought the AX50 not that long ago, I definitely would have sought out a router that supports mesh. It seems like I gave up mesh to gain AX3000 speed. Not sure that was such a good trade in my case. Do you think that the AX50 could possibly support mesh with a future firmware upgrade?

So, it looks like my options are to either use a range extender with my AX50 and be without the benefits of mesh, or to start over with either a mesh router and mesh extender(s), or just buy into the Deco system.  Thoughts?

Russ 

@Russ_G 

In your last comment, that is pretty much right with the options you have available to you.

@Tony  Of those three options listed in my previous post, which would you do?

Russ

@Russ_G 

I am not much for bells and whistles. Just a simple router and simple extender with a different SSID.

Wanted to add, if I wanted to get solid Wi-Fi coverage, say if I had a big area, I'd prob go for Deco.