GWN7610 arrived today and installed. Great device up and running but still figuring out the configuration specialities for my use cases. No flaws found so far. :-)
Found the first one:
=> WiFi 5GHz channel selection is limited in current FW 126.96.36.199 to 4 channels only (36, 40, 44, 48) in EU.
The unit ignores that we have additionally 52, 56, 60, 64 and 100 ... 140 (in steps of 4) available. It seems Grandstream is preventing Dynamic Frequency Selection (DFS) which is mandatory at frequencies above 48 for weather radar frequency protection. That declasses the unit for the moment to be used for public buildings and on bigger places. Too bad.
This means: 5GHz channel choice is limited to be only 4 out of 18 = 22% (at least in EU). This is a killing argument for an unit claiming for mass installation setup in the public if not to be corrected by firmware asap.