mannp
Occasional Visitor
Just thought I'd mention that beta 1 is working well for me on an RT-AC3200 as well.
I also just wanted to mention that I seemed to have WiFi issues with 380.65_4 whereas previously 380.65_2 had been working well and was stable. I appreciate that it is unlikely you changed anything directly related to WiFi between those two releases but even after full resets certain devices would drop off the network and not be able to re-establish a connection, despite them popping in and out of existence on the System Log -> Wireless Log. This seemed to be affecting just 2.4GHz clients, but that might be just because most of the affected devices (non-computer type ones, e.g. Sonos, Epson Printer, Withings Home) are 2.4GHz only. Disabling airtime fairness helped but only by buying a few hours.
Anyway, long story short 380.65_4 Wifi wasn't stable for me, 380.66 Alpha 4, and now Beta 1, seem to have rectified the specific issue I was having.
I am getting the same issues on version 380.65_4, but b1 is worse on my N66U as no 2.4 devices can connect at all.