I almost hate to say it but I have no obvious problems with the AC 7260. I've swapped out my N 7260 with this upgraded card in a new Yoga 2 Pro and it appears to be stable and working well.
I am seeing some performance variability though and thought I would ask to see what others are seeing from their cards - when they are working!
For testing purposes I've got the laptop set to high performance and I am about 20 feet away from the access point, a Netgear R7000. I'm transferring a single 40GB iso image and reporting the numbers I'm getting from the Windows 8.1 UI.
My connection fluctuates between 390 megabits/sec and 562 megabits/sec, I see it mostly on 520 but my actual data throughput is much lower, between 24 and 40 megabytes/sec. To me that 40 Megabytes/sec equates to about a 400 mbit/sec link so I'm wondering where the lost bandwidth may be going - or is this just an example of 'real world' and I'm doing pretty well????
40 MB/s is pretty much the best you can get out of the 7260AC. The best result that I got with Intel N 7260 is 161.28 Mbps or 20.2 MB/s on a 300 Mbps connection. Here's the SpeedTest maximum throughput test for upload since the download speed is throttled by the university's ISP:
http://www.pcadvisor.co.uk/opinion/network-wifi/3377528/truth-about-wireless-speeds/ The truth about wireless speeds - PC Advisor
Running Win 8.1 Pro x64.
I installed Intel's Centrino Dual Band Wireless AC-7260 HMWG.
Windows recognized the AC-7260 and installed a driver dated March-2013.
Download speeds averaged 30.0 Mbps.
Then I downloaded Intel's most recent ProSet package for my OS (Wireless_16.7.0_e164).
from here:https://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Wireless+Networking&Produc... Download Center
This installed an updated driver with ProSet Tools.
New Driver Date 10/14/2013
Driver Version 184.108.40.206
Testing with an Ultra 4K Hobbit movie trailer:
http://www.youtube.com/watch?v=5qJSK734DtM The Hobbit - Trailer 2 in 4k - YouTube
My speeds now average 400.0 Mbps. (More than 10x improvement!)
This is slightly slower than Ultra 4K television, however.
Hopefully Intel will continue to refine the driver.