Stock firmware has all hardware acceleration features available paired with propietary Mediatek WiFi drivers so raw performance can be better (it doesn't supports DFS channels so results can vary).
That's my guess because I spent less than 10 minutes with stock firmware.
However the WiFi speeds I get on OpenWrt are superb for a sub $100 router, my previous Mikrotik ac2 had really terrible WiFi with stock Router OS for example if you tilt your phone speeds drop to 20-50mbps (yep it supports OpenWrt but 128MB RAM it's a big limitation for power users).
I get 900+ megabit with AX200 sharkfin antenna almost touching the router and 500-700 megabits at 3.5 meters and no obstructions, 160mhz wide channel. So I would say it's the same in terms of performance as the stock firmware, if not better. But it really depends on both router and antenna orientation, so I plan to try replacing router internal antennas with something bigger and external to see if it helps.
The stock firmware is based on MediaTek's SDK which is based on LEDE 17.01. It got MediaTek's reference Linux kernel and their drivers for everything incl. offloading features, which may perform different.
Anyone here using WDS?
Anyone using DFS channels?
Which channels do you prefer?
AFAIK higher channels reduce latency.
The problem I have with WDS + DFS channels, that channel mode auto does not work on STA / repeater (AX, 5ghz) in WDS.
The connection between AP and STA gets lost after several time. I need to restart STA.
Further, the highest channel that works is 128.
I had similar issues where nothing seems to happen after flashing non ubi. What worked was building an image from commit 7119fd32d397567931e63dbbf72014e95624018f, flash it through Belkin, then flash latest non ubi.
You shouldn't do git reset [commit id] on a branch because it can screw things up. Rather, check out the ID directly after a hard reset to HEAD (which nukes all local changes on top of the currently checked out branch/commit). And if you do a git pull after that reset... You're just getting back to the HEAD of that branch, so that reset was for nothing.
The snapshot builds has been pretty stable for me. I have 2 of them running in AP mode and they have been running without issues for 5 days now after tweaking and working around minor issues mentioned in this thread (5ghz band set to 80mhz and manual channel selection with country code configured). I recommend it if you don't mind digging into the logs when you encounter issues.