Interesting, but specs says it doesn't have a USB port, which would mean I would need an interim bridge to pass my internet from the USB tethering device. There is also no future scalability to wifi 6E that I would get with using a dev board as a router.
Also, DBDC isn't working yet.
Regardless, I'm still interested in how well it performs, especially the latency.
Do not expect 802.11ax to be fully supported at this point, some basics might be there, but it's very minimal so far.
Work is ongoing for ipq807x+qcn50x4 and mt7621+mt7615e or mt7622+mt7615e (in the future probably also mt7921e), the later is further advanced at this point with two devices being supported (Totolink X5000R and Ubiquiti UniFi 6 Lite, sadly both using the rather slow mt7621a SOC). ipq60xx and ipq50xx do have a reasonable chance of future support as well, but those will (most likely) require more time than the (currently unfinished) ipq807x target.
There are no half-way usable (for 24/7 operations or AP mode) USB wlan cards for 802.11n, nor are there any for 802.11ac - let alone 802.11ax. While the RPi4 can be a fast router, it is completely unsuitable as AP - the SDIO connected onboard WLAN is slow (and limited in functionality, brcmfmac) and is only connected to a single, tiny antenna (1x1) and there are no good USB WLAN cards. Use a dedicated wireless router (or AP) for your wireless needs, this is both (significantly) cheaper and more reliable/ faster than bothering about USB (it does make sense to look for devices which are (or are likely to become-) supported by OpenWrt, but this is not strictly mandatory).
Even if I am the only user on that router in same room? I understand that these devboards aren't meant to replace a router for running the entire house, but I have a separate router for that.
What I need is something on a completely separate network, running at max 3-4 devices, with usage being 1 at a time. Slow is fine within reason, lower latency is what I am after of AX. And if possible the 6ghz spectrum not to conflict with other connections.
If USB wifi isn't good enough, what about the pcie/m.2 ones? From what I understand the RPi released a compute board with PCI express.
Again, it's best to treat the RPi as wired-only - the onboard wireless is worse than a decade old 802.11n card. It can be used in client mode for very moderate needs, but it's not useful in AP mode.
Do you want fries with that?
Really, 802.11ax at 2.4/ 5 GHz is already new and hard to do (with OpenWrt in mind) at the moment, but 6 GHz support is in its total infancy (only allowed in the US/ FCC, Europe/ ETSI will follow later, with a reduced bandwidth).
Sure, you can do that - if you manage to buy them. Keep in mind, 802.11ax cards are running hot (cooling required), are oversized (larger than the standard allows), and need a lot of power (your PCIe slot needs to provide enough, chances are that they won't - existing cards require more than the standard allows), and you need enough slots.
QCN9024, 2.4 GHz only, ~200 USD
QCN9074, 5 GHz only, ~200 USD
QCN9074, 6 GHz only, ~250 USD
(delivery time, multiple months - welcome to the COVID19 reality)
for an AP, you want (need) all three of those (I hope your compute card has 3 slots, capable to deal with oversized cards and not burning out when faced with >16 watts per card) - and while ath11k/ mainline support for them is in progress, it's not actually present yet. mt7915e (5 GHz) and mt7921e (6 GHz) might be slightly cheaper (not a lot), but availability is even worse (caveats for size/ power/ standards ignorance apply). A high-end tri-radio wifi-6e router will be in a similar price range and likely to be cheaper.
The range of 6ghz is worse than 5.8ghz due to worse wall penetration. Since it is a higher spectrum. It's only advantage is that there is more bandwidth there and that there are so far less things operating in that spectrum to conflict.
I don't understand why people keep thinking the Raspberry Pi (particularly the 4) is some sort of dev board that can't be used as a router. It's got four Cortex-A72 cores, for crying out loud, and has been shown on multiple occasions to be capable of handling gigabit connections. Pair it up with a managed switch and a WAP, and you have a setup that will blow the doors off of any consumer AIO router.
I flashed my X5000R with OpenWRT last week and it feels solidly stable so far. Sometimes the signal strength on 5G is looks weak, but I can't compare to stock because I don't want to brick my router forcing a flash of Totolink's strange .web firmware file.