@rg_village 

I just recently got myself Deco mesh and was deciding between M5, M9 Plus and X20 units. Below is my personal opinion on that topic.

M9 Plus is top of the line Deco for WiFi 5.

X20 is least powerful of Deco X-series that support WiFi 6.

On performance specs, they are almost identical. If your Internet connection is under 500 Mbit, and you don't trasfer large files inside home network, you might not notice the difference.

M9 form factor allows to wall mount or ceiling mount it.

X20 form factor is better for really heavy network utilization, tower like networking unit should have better heat dissipation.

X20 supports security standard WPA3 already, M9 - not yet. Does not make much difference for home networks. Yet, if in few years Apple releases iPhone that only supports WPA3, but M9 formware has not been updated by TP-Link, that might be an issue. Big IF, but see conversations on this forum in regard to WPA2 support, predecessor to WPA3.

Same goes for WiFi 6 - if few years from now some smartphone or tablet only supports WiFi 6 and not WiFi 5, X20 is better for future proofing your home network. That is also big IF, as current smartphones and tablets are backward compatible with older WiFi protocols. 

When I was choosing between X20 and M9, deciding factor for me was form factor. I have one of my Deco M9 wall mounted in somewhat narrow corridor between bedrooms, placing X20 or any other tower-like mesh unit there would be inconvenient. 

Also, in my case my Main and Satellite Deco M9s have good WiFi signal between them, so that they can utilize separate 5GHz backhaul, unique M9 feature. That was second selling point for me, otherwise I would have selected M5: same form factor as M9, but cheaper yet still adequate for my home network. 

In your case, because you mention thick brick walls, separate 5GHz backhaul should not be a factor for type of Deco unit selection.

Thick walls is going to be a problem for whatever mesh you deploy. I know some people might not agree with what I am about to say, but in my opinion any mesh system is not much more than just a set of advanced range extenders. If wifi extenders struggle in your house, Deco (or any other mesh system) could, too.

Still, worth to try, but make sure where you buy them from, they have good return policy. I am not returning mine, as I've got myself perfect Deco mesh, but as they say: your mileage may wary.

@rg_village 

@Alexandre. Has explained it quite well but I will differ from him on the Tri Band point

"In your case, because you mention thick brick walls, separate 5GHz backhaul should not be a factor for type of Deco unit selection."

I too have thick brick walls and I have tested both m5 and m9. At a location where m5 satellite gave speed of only 40 MBPS and latency of 20 ms at same position M9 gives me 95 MBPS and 8 ms latency on a 100 MBPS Fiber Connection.

So, I will suggest to always go For Tri Band Instead of a dual band WiFi mesh systems, until and unless your internet speed is greater tha 500MBPS in which case Wi-Fi 5 will not 

provide sufficient performance.

I think you should only go for X20 if you can provide Ethernet back haul to the satellites otherwise Deco M9 or the upcoming Deco X90(Wifi 6 with Tri Band) are the best options

@Alexandre. 

thanks for such a clear and comprehensive comparison (pity TP-Links marketing can't do this). Really helpful.

Regards,

Rob

@jthcomputers 

thanks, really appreciate you taking the time to reply.

Regards,

Rob

@rg_village Thank you for this very interesting question and thanks for all answers.

Thanks @rg_village for such an excellent question! I myself are trying to decide between the two systems.

@Alexandre. Would you consider gaming to be, as you said, "really heavy network utilization"?

I live in (for now) a 84sqm 3-bedroom apartment and are just trying to avoid connecting my modem and desktop with a lengthy cable.

I made a rookie mistake and bought ONE M9 unit second hand and now I'm stuck with the decision to by one, more estetically and practically pleasing, M9 for 1500 SEK or a 3-pack of, chunky, x20 for 2000 SEK.

(This ofcourse is based on the assumption that 2 units would be enough to cover my apartment 😁)

/Nick

@Alexandre. Agradecerte Alexandre por esta fabulosa informacion , me ayudará a tomar mejor mi desicion. Saludos a la distancia.