iPad 2 + iOS 7 = Weak WiFi Signal

A few weeks ago my SO upgraded her iPad 2 to iOS 7. No issues other then the the iPad would show an extremely weak WiFi signal throughout the house, where previously the signal was good. Other devices showed no problem in these locations so it was clearly the iPad that was at fault.

Went through all the recommended things: reset networking in iOS, changed channel on AP, tried a different AP, and still had the same problem.

I had recently picked up a dual band AP but hadn't gotten around to migrating over from the old one yet, so on a hunch a powered it on. Low and behold the 5 GHz SSID is immediately seen by the iPad, while the 2.4 GHz one is no where to be seen. This of course contradicts the usual observation that 2.4 GHz networks should have better coverage due to poor wall penetration by 5 GHz signals.

This at least provided a band-aid while I figured things out.

While looking around for more solutions I came across several forum posts stating setting their network to N-only had helped with little additional explanation. So on a whim I set my AP to N-only and with that change the iPad suddenly showed the network it previously couldn't find when it was more then a few feet from the AP.

Going through all the possible setting for the WiFi mode with the iPad in a single location:

Mode	Signal
802.11 b/g/n	None
802.11 b/g	None
802.11 g/n	2 Bars
802.11b	None
802.11g	None
802.11n	2 Bars

Tried this with a different brand AP and saw the same results. That's good enough evidence for me. There is clearly an issue with iOS 7 and how it handles mixed mode wireless standards - specifically non-N or modes including B. Since it isn't all iOS 7 devices there has to be some other factor - likely firmware loaded at run-time by iOS for the wireless chipset in the iPad.

Changing the setting fixes things while the iPad is home, but does little everywhere else since almost all routers/APs will be set to some mixed mode out of the box for maximum compatibility. 

I'm waiting for a fix Apple.