I did some test with my Surface Pro 3...
Router: Asus RT-AC68U
Connection Speed: 866,5 Mbps
Local xfer speed: 280 Mbit/s when copying from my Nas.
Internet speed: 105,5 Mbit/s down and 11,9 Mbit/s up on my 100/10 connection.
Other details optional. The speed tests was done on 5ghz