I am still testing this but these settings are pretty great so far, I am using 6687 beta, I am able to stream 720P movie on the 2.4GHz ~350+ feet from the router in two directions, the garage direction has a weak spot but is better now after these settings and no ios drops so far with the exception of the garage area. iPhone 6+ ios 8.3, tested also with wifi analyzer on my samsung note 10.1 1st gen.
I have the 2.4GHz beamforming on and beamforming on for 5GHz!
I also have no 2.4 or 5GHz guest networks enabled, as if I do enable the 2.4GHz guest network, my 2.4GHz network develops weakness and drops quicker.
2.4 band general
wireless mode = Auto optimize for xbox and b/g protection both unchecked
channel bandwidth = 20/40
control channel = 8
extension channel = Below
Authentication Method = WPA2- Personal
Protected management frames = Disable
Network Key Rotation Interval = 3600
2.4 band Professional
enable radio = yes
enable wireless scheduler = no
set AP Isolated = no
Roaming Assistant = Disable
Enable IGMP Snooping = Disable
Multicast Rate(Mbps) = Auto
Preamble Type = Short
AMPDU RTS = enable
RTS Threshold = 2347
DTIM interval = 1
Beacon Interval = 200
Enable TX Bursting = Enable
Enable WMM APSD = Disable
Reducing USB 3.0 Interference = Enable
Optimize AMPDU aggregation = Disable
Optimize ack suppression = Disable
Turbo Qam = Enable
Airtime Fairness = Enable
Explicit beamforming = Enable
Universal beamforming = Enable
TX power adjustment = 100%
5 GHz band general
wireless mode = Auto optimize for xbox unchecked
channel bandwidth = 80
control channel = 157
extension channel = Auto
Authentication Method = WPA2- Personal
Protected management frames = Disable
Network Key Rotation Interval = 3600
5GHz band Professional
enable radio = yes
enable wireless scheduler = no
set AP Isolated = no
Roaming Assistant = Disable
Enable IGMP Snooping = Disable
DTIM interval = 1
Beacon Interval = 200
IEEE 802.11h Support = Disable
802.11ac Beamforming = Enable
Universal Beamforming = Enable
TX power adjustment = 100%
All antennas pointing straight up.
You may need to adjust some for your own area, but
so far this is working pretty great.
newegg has a refurbished rt-ac87u for $150
http://www.newegg.com/Product/Produ...3015-Index-_-WirelessRouters-_-33320221-S2A8A