Hi, I confirm this procedure solved the problem for me (lenovo yoga 2 pro with AC7260 installed, 8.1 enterprise 64bit).
It connects above 500Mbps in AC to my D-Link DL860 router and I can transfer files with 30MB/s sustained from a samba share.
All settings at default:
802.11n channel width for 2.4GHz -> auto
802.11n channel width for 5.2GHz -> auto
Ad Hoc channel 802.11b/g -> 1
Ad Hoc QoS Mode -> WMM Disabled
ARP offload for WoWLAN -> Enabled
Bluetooth AMP -> Enabled
Fat Channel Intolerant -> Disabled
GTK keyring WoWLAN -> Enabled
HT Mode -> VHT Mode
Mixed Mode Protection -> CTS-to-self Enabled
NS offload for WoWLAN -> Enabled
Packet Coalescing -> Enabled
Preferred Band -> 5.2GHz
Roaming Aggressivness -> Medium
Sleep on WoWLAN -> Disabled
Throughput Booster -> Disabled
Transmit Power -> Highest
U-APSD -> Enabled
Wake on Magic Packet -> Enabled
Wake on Pattern Match -> Enabled
Wireless Mode -> 802.11a/b/g
Also, power management is enabled (Allow the computer to turn off this device to save power and Allow this device to wake the computer, both enabled)
Thanks.