Those numbers are way below 1Gbit, I would expect at least 900Mbit, and anyways have no intention to assemble a router myself.
The "real world" for you means spending time tinkering with RPI4 which is a general purpose single-board computer, not a router. I do a lot of tinkering but I am simply choosing to not do that for the hardware of the router.
This thread is a perfect example of what a toxic community is: I politely ask about which device could work for me, specifying that I do not wish to use RPI4s, and now the thread is exclusively about RPI4s, being replied by people that do not know how to answer my original question (which was not about RPI4s).
Additionally, by your own admission "I got myself an RPi 4 since I've been recommending it to people": I am glad you finally tried it out, but no thanks, I do want advice from people that recommend hardware that they do not own/have owned before, even if you have stopped doing that now.
The fact is there's nothing that handles 1Gbps and is reasonably priced and anywhere near as highly available other than RPi4. So that's why you're getting that recommendation. You clearly didn't read anywhere near to the end, by which my experiments showed full gigabit routing and shaping at about 15-20% of one of the 4 CPUs, and also you probably didn't notice that thread started almost 2 years ago when the RPi4 was brand newish.
Look, if you don't want our advice, don't ask for it. Our advice is you have to do either RPi4, some other SBC that is way less available, or an x86. There's nothing else that routes and/or shapes a gigabit reliably in real world conditions running OpenWrt today.
Also I assure you any toxicity involved is entirely down to making claims like this:
Which is approximately like showing up to a Harley Davidson convention and saying "I'll never own an American motorcycle they're all crap and can't even begin to compete with my Honda".
In the real world, the nbg6817 (ipq8065) can route at something like 500-650 MBit/s (swconfig, just under 400 MBit/s with DSA and multi CPU-port support) - reducing that to just under 200 MBit/s with SQM enabled.
I use fanless x86 for routing and guest WiFi and three C7's as dedicated AP's. It's just not worth fussing with one combinded router/AP and another AP-only. Let routers route/shape/VPN and AP's handle WiFi. Anectdotally, WiFi roaming works best between identical hardware/OpenWRT versions.
For an all-in-one WiFi router solution, the Belkin RT3200 is reasonably compact with no external antennas and will get you closer to routing Gigabit than an ipq806x based unit, but an ipq806x all-in-one with external antennas will probably give you better WiFi coverage.
However, you will have a difficult time finding a more compact unit in a nicer case capable of routing and shaping full Gigabit than a NanoPi R4S 4GB, paired with an inexpensive used Wave 2 WiFi 5 all-in-one router for an AP with extra switch ports (if more ports are desired).
The Archer C7 (or A7) still has a lot going for it - it can be found used on ebay practically for free and is OK as an AP. But it is showing its age. I replaced a 3x3 Wave 1 Archer C7 AP with a 2x2 Wave 2 (MU-MIMO) AP to get faster 5GHz 802.11ac WiFi for example. There are plenty of used Wave 2 options for not much more than a used C7/A7.
When you say "ipq806x all-in-one with external antennas", do you mean something like the R7800?
The floor where I will put this router/AP will not see much LAN/WiFi usage, so it's better to use something compact there.
At some point I considered getting another C7 also because of what @Gruntruck said; what Wave 2 model should I look for to get good OpenWRT support? In the end I am going to need WiFi roaming working for the mobile devices.
Yes - I mean something like the R7800 for an ipq806x device.
If the floor where this router is going won't see much LAN/WiFi usage, the Belkin RT3200 seems like a good choice. It has a lot going for it as a router and will also provide moderate WiFi coverage.
A used EA7500v2 (MT7621) or even an EA7500v1 (ipq8064) would make a decent Wave 2 AP for $30-$40 used. If you're feeling adventurous, a used EA6350v3 (ipq40xx) has a small visual footprint (why I like mine), but also requires replacing the board-2.bin file with one from a NoTengoBattery build to get good WiFi performance. The EA6350v4 (MT7621) is not yet supported, but probably soon will be - you could keep an eye on that if you're not in a hurry. There's others - just browse the table of hardware.
My three C7 AP's are overclocked to 1GHz and are able to saturate 2x2 802.11ax on 80MHz channels. They support WPA3 in latest release, roam fine, support VLAN and give 500Mbit/s in iperf3...it will take a long time until they are obsolete.
C7's are more than adequate for most uses and it's hard to beat their used prices if that is an issue. Me personally, I'd spend another $10 or $20 for Wave 2 if I were adding an AP today, but I can certainly see it not being worth it to others.
Back when I had a C7, I found I got more throughput from my EA6350v3 than the C7, particularly as distance increased from "plug it in to the Ethernet port instead" range to more typical distant locations around the home. I never tried overclocking the C7 though, so I can't say if that would have made up the difference.
I wouldn't consider VLAN or WPA3 a distinguishing factor. I can't recall owning a target that did not support those capabilities after they were supported by the OpenWrt firmware. ipq40xx targets do insist on having VLAN ID's 1 and 2 to themselves, but there's no shortage of other ID's to use. The C7 does lack Wave 2 Multi User capability (the MU in MU-MIMO), but absent a use case with multiple simultaneous high demand clients, that may not be too important either.
How did you overclock them? I might give this a try. I agree, they are very good and was also surprised to find a V2 so easily and so cheap.
Thanks, I have read your previous messages and recommendations about the Belkin and about the EAs and finally settled for a R7800 because I found an used one for 68$; I could have got it for 55$ if I waited longer, but I am okay with this price.
The reason why I went for this model is that I would like to serve the most distant corners of the house with it (I will place it roughly in the middle) while I use the C7 on the top floor alone.
My only remaining fear is that the different WiFi chipsets won't play well along for WiFi roaming; I will do some tests this weekend
With everything running OpenWrt, they should play well together.
FWIW, I found roaming more trouble than it was worth in a two story home. The few roaming clients in our home (phones and a laptop) would stick with a sub-optimal AP or band too long. And when the AP selection algorithm in stationary clients (the majority of clients in the home) did not make the best choice, having the same SSID (and password) assigned to multiple APs on different channels for roaming made it difficult to force a stationary client to manually pair with the desired AP and band.
So I settled fairly quickly on naming floor 1 SSIDs: floor1, floor1-IOT, floor1-guest, floor1-5G, floor1-5G-IOT and floor1-5G-guest. Same with floor 2. For stationary clients, manual set up is once and done. The few roaming clients have a floor1 and floor 2 AP saved in them, so it's not much trouble to switch when needed.
Someday I may try experimenting more with reducing 2.4 GHz radio power so that roaming clients will select faster 5 GHz over slower high signal strength 2.4 GHz AP's; and balancing radio power between the AP's on each floor to optimize coverage overlap, but the floor 1 ceiling (floor 2 floor), while opaque enough to WiFi to affect performance in our home, is not so opaque as to make optimizing coverage overlap easy.
Roaming does not work well when mixing 2.4 and 5. 2.4 has longer range and clients will always prefer higher ERP even if it is suboptimal. 2.4GHz in itself alone does not work well on Archer C7. It is buggy and usually goes down after couple of days.
People who do this for living and build "serious" WiFi networka involving multiple APs and roaming almost never use 2.4GHz. The usual mistake DIY:ers do when setting up roaming network is to keep power high and not do channel planning. The trick is to bring channel reuse to minimum and keep power at level where clients do not "hang" on distant AP's.