2016 is the year of multi-gigabit 802.11ad WiFi. At least, according to Qualcomm, it is.
WiFi speeds of up to 4.6Gbps, High-speed multi-gigabit 60GHz WiFi: Coming soon to a TP-Link router near you.
https://forum.arduino.cc/index.php?topic=350002.msg2414954#msg2414954
The second generation Yun (Tian) supports 5GHz WiFi.
The third generation Yun supports 60GHz WiFi?
There is no fastest, only faster.