@David-TP 

I have 2 floors to cover and their all wired in series. So if the ground level one is obsolete. I i can go 2 pods with the first in ap mode I could be cheaper off.

In reality I'm changing to faster pods because I have 1 gig connection and these M4 isn't cutting it. Goes to max 650 Mbps.

What do you think?

  @Hotrodh3ll 

Start with one Deco pod per floor. Measure speeds and WiFi signal reach. If not satisfied, add more pods per floor, connecting them to the Deco pod on the same floor which has Ethernet backhaul.

Note that every new WiFi standard provides faster speeds, but for shorter distances and more sensitivity to WiFi signal obstacles (walls, etc) and interference (WiFi from neighbors). M4 is WiFi5, Deco X-series such as X20 is WiFi6.

Depending on your house layout and your WiFi speed expectations one pod per floor might not be enough, but one pod per floor is a minimum to start with.

Also, I would suggest you to consider a but more powerful Deco X50 or X55. 

  @Hotrodh3ll 

All Deco mesh systems work the same. It is recommended to turn off router WiFi. Without WiFi coming from the router, you will need one Deco unit on that same floor where router is.

To make it really, really simple: number of floors at your house is initial number of Deco nodes at your house. How many floors does your house have?

For optimal coverage and performance, it's recommended to have one pod  VAT Tax near the router downstairs, especially in larger homes. However, with newer systems like the x20, you may achieve sufficient coverage with just two pods. Assess your home's layout and size to determine the best configuration for your needs.