I have a sp3 with the 9/9/14 firmware update...at home I have no problem, IF i have one ssid for the 2ghz band and a complete different ssid for the 5 ghz band. If i choose to connect to the 5ghz ssid it connects at 866mbps, in other words wireless AC.
At work is another story we have multiple access points using the same SSID for both bands. It seems like when you have the same ssid for both bands its automatically selects the 2ghz band in lieu of the 5ghz band. Its kind of funny that we put an access
point right beside the surface at only 5ghz band. The others access points had 2ghz band and 5ghz band no matter how many times i disconnect and connect the wifi and connect to the same ssid it automatically select one of the access points on 2ghz band even
if it was 100 feet or more away. We disconnect that access point and automatically select another access point that was on the same 2 ghz band that was a little closer.
So in other words the surface pro 3 behavior is that is selecting the 2 ghz band not the 5ghz if the ssid are the same. The only way to force it is to create a different ssid for 5 ghz band. Thats why you only see 144mbps or less using the same ssid because
i guess is using Wireless N 2ghz at 150 mbps. Wireless AC does not work on 2ghz band.
Those are my finding. I dont know why Microsoft have taken son long to fix this issue. I don't think is hard to fix. Other wireless AC adapters have better logic on selecting the best connection.
I have been seeing the same exact issue with my home network. For now, i've split it into 2 frequencies, but i *really* don't think thats an acceptable solution - the network adapter should always choose the best frequency, and with all my other dual band
devices in my house, that's always 5ghz.
So - Microsoft, at the very least, please allow a setting in the driver configuration so that I can specify to use the 5ghz band on a combined SSID....or better yet, fix the logic :-)