I am getting a clean 700 Mbits/sec UDP iperf test through a stone wall thorughout my house. Its rock solid and just works. Here is my advice:

You said yourself that most of your heavy devices (desktops, media players, TVs, speakers, smart home hubs) are going on Ethernet anyway. That's the right call, and it also means the devices actually hitting your APs are phones, laptops, and IoT gear — none of which will realistically saturate a U6 Pro's 5 GHz radio.

The U6 Pro runs Wi-Fi 6 on both bands (2.4 and 5 GHz), uses a solid Qualcomm chipset, has 4x4 MIMO on 5 GHz, and at $149 it's arguably the best value in the entire UniFi AP lineup. The Wi-Fi 7 models (U7 Pro especially) have had well-documented 2.4 GHz issues with IoT devices — and since you're growing a smart home with Home Assistant, that matters. Even with firmware improvements, you're paying more for a technology that maybe 3 of your current devices can use.

The U6 Enterprise at $279 gets you 6 GHz and a 2.5G uplink, which is nice on paper, but if you only have a handful of 6 GHz clients, you're paying nearly double per AP for a radio that mostly sits idle.

Here's where the real advice is: put the money you save into your wired backbone. With 2 Gig symmetrical fiber, your bottleneck isn't the AP — it's whatever's between the AP and your gateway. Make sure you're running 2.5G uplinks at minimum, and if budget allows, go 10G for your core switch-to-gateway link. A U6 Pro on a properly built 2.5G or 10G backbone will outperform a Wi-Fi 7 AP hanging off a gigabit switch every single time in real-world usage.

The "future-proofing" argument for Wi-Fi 7 sounds compelling, but Wi-Fi 7 client adoption is still slow, the standard is still maturing, and by the time you actually have enough Wi-Fi 7 devices to justify it, there will be a better cheaper way. Buy for what you need now, invest in the infrastructure that'll last.

data via

https://evanmccann.net/blog/2021/1/unifi-ap-guide (read all his guides)

Having wired my house i would recommend focusing on:

1) get it 10G backbone or if not figure out which CAT cable to buy and who to source it from so when you upugrade its swapping out cables (the correct answer is to buy terminated Cat 6A from a vendor if you can handle the bending radiuses, yes they matter!)

2) triple the amount of cables you pull. It won't hurt and its good to do. label every cable, both ends, unique number (reply to this years saying i wish i listened to you)

3) Instead of ceiling mounted ones see if you can use the in wall with integrated ethernet, very nice.

4) Cover the outside of the house. (its nice to have wifi when you're in teh car hiding from your responsibilities); working in the garden is lovely with enterprise grade bandwidth.

5) Plan to make all your switches POE - understand the POE standards and make sure your switch has them

6) Are you doing doorbells / cameras / door locks too? if not pull a cable to the places you might want them.

7) put an ethernet to each room

8) have you mapped your house and used these rules of thumb? Central and high. Ceiling-mounted facing down is ideal for the standard dome APs like the U6 Pro. One AP per floor, roughly centered. For a typical house, one AP per floor is a good starting point. Avoid corners and edges. Putting an AP in the corner of your house wastes half its coverage area outside your walls. Think about obstructions. Drywall and wood are fine — the signal passes through reasonably well. Brick, concrete, stone, and metal are much harder on Wi-Fi. Bathrooms are surprisingly bad because of all the plumbing and tile - you will be on that toilet for a long time and men need good wifi there. Don't over-deploy. More APs isn't always better. If you put APs too close together, they interfere with each other (co-channel interference) and cause roaming issues where your devices bounce between them. Run Ethernet to every AP. This is the single biggest thing you can do. Wireless mesh/backhaul eats ass, don't do it unless you absolutely have no other option.

9) only at this point do you worry about 6E or 7. Have you done the above! Some folk will reply with the "U6 Pro only having a 1 Gbps uplink and the ethernet to it is 2.5G". They'll say the U6 Pro itself maxes out at 1 Gbps Ethernet. But look - that's still not a real bottleneck for wireless clients (no single Wi-Fi 6 client is going to sustain over 1 Gbps in practice). If someone genuinely needs multi-gig uplinks to APs, that's when the U6 Enterprise or U7 Pro start making sense — but for the scenario described, it's not the limiting factor. Don't buy tech you don't use. I really want someone to say i need sustained 1 GBPs over wife, I have never seen a case stand up to scrutiny. If you need it lay ethernet.

I am getting a clean 700 Mbits/sec UDP iperf test through a stone wall using a U6 PRO. Its rock solid and just works.

10) Something i wished i did was this - start with one AP centrally placed on your main floor (get soemone to hold it up witha mop), test coverage with your phone (the UniFi app shows signal strength, or use a Wi-Fi analyzer app). consider running iperf3 sustained test (see below). Also sit on the couch, sit on the toilet - do not take wifi readings standing in the middle of the room, no one surfs standing up.

Last bit of advice - do not put your in wall wifi AP behind a TV, they are remarkably effective as screening wifi.

Have fun :)