I have 3 Deco M5 providing mesh network coverage in my 2500 sqft home (not hard wired to each other). I have a 1 Gigabit connection from the Internet company.

When I connect via Ethernet cable to the main Deco M5, I get about 700 Mbps download speed. When I connect with Wifi, the maximum I get standing right next to the Deco M5 is 225 Mbps, and it drops to 100 Mbps or even 10 Mbps on the Deco M5 that are further away from the main Deco M5.

1. How do I increase the Wifi speed from the Deco M5 over wireless? I expect to get the advertised 400-867 Mbps over Wifi when standing right next to the unit but getting much less.

2. When connected through a wired connection, why am I not getting the full 1 GBps speed through the Deco?

3. I have often found my device will connect to a Deco M5 that is much further away even though another Deco M5 is much closer. Why isn't "seamless switching" occuring to always make sure I am connected to the closest M5?

I am going to move to a larger home with 4500 sqft and now considering extending my mesh network. I am leaning towards the Deco M9 or one of the X series with support for Wifi-6.

1. Is it worth keeping the existing Deco M5 and extending with M9 or the X series or shall I replace the entire mesh network with new X series devices? Is there a benefit to having more Deco units even if some of them are slower speeds (e.g. M5) or better to have fewer Deco units that have faster speeds?

Thanks.