Mesh Wi-Fi versus wired access points at home

The honest version of the mesh pitch: mesh exists because running Ethernet cable through a finished house is expensive and disruptive. Everything else about mesh is a compromise made to avoid that cost.

Sometimes that compromise is exactly right. Often it is not.

What wireless backhaul costs you

A mesh node that connects to its parent over Wi-Fi uses airtime twice for every packet. On a two-radio node sharing the same radio for clients and backhaul, that roughly halves throughput per hop. Two hops from the router, you can be at a quarter.

Tri-band mesh mitigates this by dedicating a radio to backhaul. It genuinely helps and is the feature worth paying for. It does not eliminate the problem, because that dedicated radio still contends with your neighbours.

When mesh is the right answer

You cannot run cable, for reasons of tenancy, listed building status, cost or disruption.
Your house is up to roughly 200 square metres over two floors, conventional construction.
Peak demand is streaming and video calls.
You want one app and no configuration.

When wired access points win

You have, or can run, Ethernet to two or three sensible locations.
Thick stone, brick, or a lot of metal in the structure.
Multiple people on video simultaneously.
The building is long, split-level, or includes an outbuilding.

Two wired access points beat five mesh nodes essentially every time. This is not close.

The middle path most people should take

Run one cable. To roughly the middle of the far half of the house. Put a proper access point there — a UniFi U6+ costs less than most mesh satellites. Then, if a corner is still weak, add a single mesh node hanging off it.

One cable converts the worst case (three wireless hops) into the good case. Even a cable clipped along a skirting board and painted does the job.

Practical settings that help either way

Put the router or main node central and high, not in the cupboard under the stairs.
Use one SSID across all bands and nodes. Separate SSIDs per band is 2010 advice.
Leave 2.4 GHz on for smart home devices but do not expect performance from it.
Place mesh nodes halfway to the problem area, not in it. A node at the edge of coverage extends a bad signal.
Check whether your ISP router can run in bridge mode. Two NAT layers cause problems that look like Wi-Fi problems.

And the part the box does not mention

Wi-Fi 7 mesh systems quoting 320 MHz numbers are quoting figures you will never see in a house. Buy mesh for its backhaul architecture and its software, not for the number on the front of the box.