This is a thread right in my wheel house. Been an avid 802.11n Atheros 9380/9390 user. Did you measure net TCP throughput yet? At 6 GHz how much worse is penetration of walls vs. 2.4 GHz 802.11n at say 100mW and using some 3 dBi omni antennas? Did you re-use dual-band 2.4/5.8 GHz antennas?
No testing has been done since the module needs additional drivers in Linux to perform as an AP. I'm still working on it but fighting other battles ATM for more important things like switching 5G providers.. .well, just how it's billed and better performance. I ditched TMHI for $55/mo for TMO voice SIM and built my own "modem" instead that gets 4-5X the DL speed and is cheaper @ $48/mo and can be used with my phone by moving the SIM which cuts $15/mo in phone costs as well. So, makes up for the expense of the modem setup I came up with and will pay it off within a year or so in the savings. Plus the TMO SIM has an additional 40GB/mo of HS data which is more than the current phone plan @ 10GB/mo.
As to prior testing though with the AC1200 card I had good speeds but only 866mbps as AC maxes at that. With an AX AP though and AX411 wifi adapter I could hit 1.7gbps when combining the two bands into a single pipe.
With the current WIFI-7 cards they're a bit of a pain but, most of it's the newness with a single driver release and the other issue is my laptop likes to spazz out occasionally with the touchpad which usually resolves with a suspend/resume but, the driver for wifi complains about a power fault and BSODs occasionally.
My current AP though which lacks 6ghz does cover things corner to corner in 1300sq ft w/ full speeds on 5ghz. So, I don't think 6ghz will be much difference though max speeds would likely be in the same room w/o obstructions. I still think though it will beat the AP with the 320mhz of bandwidth vs 160mhz.
BE is just a bit of a toddler at this point still since it's not certified and lacking 100% drivers to enable features still in some cases. There's a couple of QCA options out and they're listed above but, client vs AP series makes a big difference in costs / heat / performance. The higher end options I found were in the $500 neighborhood for an M2 but, then you have cheap AIO options like TPL that sell for about the same but likely have worse specs inside.
It's just a waiting game at this point and $40 isn't that big of a gamble considering it can still be used as a client option if it doesn't get enabled for AP use.