Add me to the list of those having problems with the AC7260 not connecting after sleep. There are other problems as well (frequent disconnects etc. including 3x while writing this post!) but I'll try to stay on topic.
I have a Dell M6800, running Windows 7 Pro 64 bit. I am using the 17.0.5 driver. Windows and all other drivers are up to date. As a side note, Dell's last update on 8/3/14 is the 16.1.3.1 driver.
The best solution I have come up with so far(I don't think it has been suggested previously) is as follows:
After waking the computer from sleep and finding that the adapter either won't connect or has connected with "no internet access", I open the Intel PROSet/Wireless WiFi Connection Utility. I do this by double clicking on the icon in the 'Show Hidden Icons' area of the taskbar.
Then I click on 'Profiles' and then specifically select the one profile that is listed there.
Then click on 'Connect'. This seems to bring the 7260 back to life and actually connect. It isn't instantaneous, but it usually only takes about 15 seconds.
Other solutions I have tried: Selecting my network and choosing 'connect', clicking on 'Details' and selecting 'repair', resetting PROset, turning the adapter on and off and just about every other suggestion listed here. I have also tried a replacement AC7260 card and it behaved exactly the same. At least they're consistent!
I completely agree that we shouldn't have to do any of this, but for now this at least seems to work for me. I have quite a few devices connected to my router (old and new smartphones and several other laptops with far "lesser" wireless adapters) and none of them have any issues whatsoever.