Just got a new Lenovo Carbon Gen2 with a Wireless-AC 7260. I have a Carbon Gen1 and I get around 70 to 80Mbps downloads. I was only getting around 4Mbps on the new Carbon. I tried everything on here. The last thing I just did was strip all of the drivers, and unload the oldest driver and let it reinstall.
Now I'm getting 80Mbps downloads.
Driver info:
Date: 9-19-2013
Version: 16.5.3.6