I am using an HTC One with Rogers. Ever since the KitKat 4.4 upgrade, my WiFi doesn't work properly. I am not able to connect to WiFi access points. Attempting to connect to any WiFi network will give me the error "Failed to connect to network". I cannot turn off the WiFi either. The button will grey out for a while, and then remain in the On state. Rebooting the phone will give me back control of WiFi for a while, but it will soon not work again.
Also, since the 4.3 upgrade, my Google Text-to-Speech will continuously crash when I use Google Maps for navigation. Once it crashes, Maps will not be able to read out street names. I was hoping the 4.4 upgrade would fix this issue, but this is still broken. My wife's phone has the exact same issue.