256-QAM is not part of 802.11n standard. HT MCS7 ends at 64-QAM.
The above mentioned iPhones support up to HE MCS9 on AX@2.4 GHz. This is indeed 256-QAM but 11ax, not 11n.
HE MCS9 on a 20 MHz 2.4 GHz channel is 115 Mbps PHY rate: https://mcsindex.com/
And this is more theory in crowded 2.4 GHz band and the best case scenario for signal to noise ratio. Double the rate for a 40 MHz channel and you are in the range of what @Jack007 measured.
Officially it's not, but some devices support it. So with it enabled I know that my phones link speed is 173 Mbps instead of it's usual 144 Mbps.
I believe this pull request also depends on this one to actually function. Although, you'd need to make further changes to get any of this working at this point anyway. And that's why I tested with ImmortalWrt instead, since it's already got a setting for it.
I'm saying that the 2.4GHz issue doesn't seem to affect all devices that'll use 802.11ax. For example, I know that the Google Pixel 8/7 as well as Intel AX210 modules have no issues at all and can easily achieve 150 Mbps. But phinn said that his iPhone 15 can't get more than 55 Mbps when using 2.4 GHz via the GL-MT6000, yet he'll get 150 Mbps from his Ubiquiti U6 when he's using the same settings as the GL-MT6000.
If you limit 2.4 GHz to N mode and perform a speed test you'll get around 40-110 Mbps. But if you install the GL.iNet beta firmware that uses the MTK driver then people are saying that you should consistently get better speeds. So, I mentioned 256-QAM applying to 802.11n because the MTK driver already supports that whereas the mt76 driver doesn't.
Okay, I understand. Thanks for explaining. I spent a lot of time on getting unsupported WiFi capabilities out of my E8450, to be able to use AX mode without being limited to single digit upload speeds on Apple AX capable devices: [Solved] 802.11ax worse than 802.11ac with mt76 driver? To agree on this and fix the performance bug created by unsupported modes took over one year.
Maybe you are right that this time enabling out of 802.11n standard modes is only a benefit and does not produce problems. For me this is an argument to not buy GL-MT6000 at this time.
Are you using immortal firmware selector? Snapshot or release? Sometimes their builds fail to load
If you only need AP then probably Netgear WAX206/Asus TUF-AX4200 can already do the job, you don't need dual 2.5G port
MT6000 seems to have better specs than the ASUS AX4200 (4x4 radios > 3x3 radios for multiple 2x2 clients) and the MT6000 has radio coverage pretty similar to the R7800 (good range, I have been reading the WAX206 threads for a while - there are intermittent complaints about coverage with the internal antennas). MT6000 is probably overkill as an AP but I do like really good internet. 
For $135 the MT6000 is a great deal and beats out most in the bang for buck category. 
Enabling 256-QAM in ImmortalWrt didn't help though. So, it either doesn't work correctly in ImmortalWrt or the issue is elsewhere. But I was eager to test it, since the first thing I noticed when trying the GL.iNet beta firmware was that my link speed had increased.
I think the slower 2.4 GHz (802.11ax) speed observed when using some Apple products could be a separate issue, much like it was for 5 GHz. However, I can't prove it since I don't own any Apple products.
I used the firmware selector, selected a snapshot and didn't keep any settings when installing the firmware. And everything seemed to work, but I reverted back to OpenWrt once I was done testing.
I've had my eye on the GL-MT6000 for some time now. After some recent headaches with my much loved RT3200s, I finally broke down and ordered a GL-MT6000, which I have up and running now as a dumb AP. Nice little unit thus far. 
On the mt76, WED was only enabled in the TX direction (from RT3200/E8450 standpoint). However, from what I can tell, WED on the mt79 operates bi-directionally (on the TX and RX path).
Can anyone confirm if this (bi-directional WED) is true on the GL-MT6000?
More thoughts on WED here... on my mt76 (RT3200) based devices, I found bridger would work for some amount of time--maybe minutes, maybe a few hours. But ultimately, flows would stop hitting ppe0 and would not work again until restarting the bridger service (or a full reboot).
I am seeing the same behavior now on my new GL-MT6000. Flows stop hitting ppe0 after just a few minutes. I was having to run this patch (@anon58727419 has noted it was not meant to be the fix):
FYI, building the same patch into my GL-MT6000 build keeps bridger running as expected.
Anyone else noting the same behavior?
I have received my GL-MT6000. Extremely fast delivery from China, I had expected a month, it was only a few days.
Does anyone know when a stable release of OpenWrt for GL-MT6000 will be released?
Or can I take the snapshot release as a noob and install luci web UI?
What does the roadmap and maturity level look like at the moment?
I use the latest snapshot and it’s great so far. You can request luci and luci-ssl packages in the firmware selector so you have Luci after flashing. Just make sure that you use the sysupgrade bin when flashing.
Also you have to manually enable HWNAT from Luci and WED in configs.
what is that?
You could try **23.05-**Snapshot instead of Main-Snapshot. 23.05-Snapshot is a preview of the next 23.05 stable series release.
I've tested it with 23.05.3 dev branch and main snapshot branch. Peronally I still recommend just doing a sysupgrade from snapshot then install luci. A lot of little improvements, kernel 6.1, newer mt76 driver etc. It's perfectly stable. You can enable HFO and WED as desired I use both.
Hi all. First post here, newbie. I bought the GL-MT6000 after a recommendation in a Swedish tech forum discussion regarding my slow VPN speeds. This router solved that problem easy.
I would like to use Openwrt but no stable release yet and after flashing my device with latest snapshot I reverted after a couple of hours messing around. Failed to get wireguard working and some lack of intuitive guides about what to do first and what packages to install.
I will try at a later time when I feel more comfortable and have more knowledge about openwrt. Great forum btw. Thanks.
hi naftali use firmware open selector and update via luci snapshot
sorry for my english i come from geneva
Hi buddy, on kernel 6.1, does WED work fine on wireless?
I cant find this package https://openwrt.org/packages/pkgdata/luci-app-wireguard
luci-app-wireguard is a Killer-App for me
I need to wait? Or is it user error?
The WireGuard status page is now a part of luci-proto-wireguard, so you no longer need luci-app-wireguard.
