@i3yron There is perhaps a way to create a mesh with your Archer and your Deco, look at this: https://community.tp-link.com/en/home/forum/topic/704874.  If this is not possible yet, it will perhaps be possible later.

If this is not possible, I believe you understood how to use the Deco.

If you go for the second option (keep router), you must set the operation mode of the Deco to AP, otherwise it is not allowed to plug two Deco into the router.  In Router mode, one Ethernet port of the main Deco is dedicated to the connection to Internet, it cannot see another Deco via that port.

  @yves_b I tried what was mentioned in the article, but even updating firmware on both the Archer AX10, and the Deco X55, but the Deco didn't seem to offer any easymesh support, and the Archer can't find it.

I couldn't find in the initial setup where to put the Deco in access mode, so I just plugged it into my router.  It set up it's own network, for example, if my local network is 192.168.0.1, then the Deco pulled an IP from the DHCP server running on the Archer AX10, and then formed it's own subdomain 192.168.68.xxx

After setup, I can, thru the Deco app, see the X55, and it says it's running in router mode.  Is there any dissadvantage to doing this?  Just having my priority stuff run on the Deco network, and other stuff on the old?

Should I just plug the main deco into the modem, and let deco handle everything?  What do I do with the old Archer AX10?

  @i3yron Difficult to recommend something, with the minimal info you provide.  Are you satisfied with two independent wifi networks?

With your Archer running as a router router and Deco running as a Router:

- You have a double NAT, difficult for some usage (some applications)

- all Deco traffic goes via the main Deco, perhaps not optimal performance wise

- it is not allowed to wire a satellite Deco into the Archer router

If you run the Deco in AP mode, you cannot use some features of the Deco, such as Parental Control.