In the current setup I'm using 3 * 'Xiaomi Mi Router 4A Gigabit Edition' (xiaomi,mi-router-4a-gigabit, ramips/mt7621) as 'main access points' which have thus far worked well. I bought these new specifically for this purpose and never allowed them access to the 'net before flashing OpenWRT. I disable routing/firewall/dhcp on these devices, they are pure access points. I'm also using a number of repurposed devices from different manufacturers - Belkin, Technicolor, Netgear, Asus, D-Link and probably some others I forgot about - for local access points and as local switches, again with routing (etc.) disabled. There are 6 different wireless networks (LAN, guest, ipcam, IoT, OPS and the open but slow 'snigelnät') which are trunked to the APs over VLANs.

I'm running a dual-stack network (IPv4/v6) using DHCPv6 for deterministic IPv6 addresses on hosts, all that is handled by the virtual router running in a container on Proxmox on the server-under-the-stairs. This is also where I run Wireguard (VPN) and adblock.

Maximum wireless speed varies depending on which AP you're connected to, in practice up to about 550 Mbps when using the Xiaomi 4A APs (advertised as AC1200). Range is sufficient for me to have a WiFi connection when I'm in the middle of a 3.5 hectare field on the opposite side of the road, about 150 m and a number of walls plus some trees separated from the nearest AP.