All in all, I have around 70 wifi devices in my apartment. That might sound like a lot of devices (it is), but I'm a nerd and I like to tinker with lots of smart home stuff and I also have a lot of computers and gadgets.
Also, because I live in an apartment complex, there is a ton of WiFi noise from other neighbors. There are around 20 different WiFi networks within range.
I went through multiple WiFi routers (including high end $300 ones), but I was rarely able to get over 100 Mbps.
When I upgraded the Unifi UAP‑AC‑HD, it was like flipping a light switch. All of my wifi problems went away, and I was able to get 300-400 Mbps in pretty much every room.
I get that WiFi 6 is great and all, but at this point, I'm not really sure what I would be gaining by upgrading. The UAP‑AC‑HD is on the high end of the previous generation, and at least for now, it's good enough for me.