WiFi is horrible under iOS 8. Cuts out all the time and I get terrible speeds. I still have my old iPhone 5 running iOS 7 and when my iPhone 6 is crapping out, my iPhone 5 is fast as ever. Definitely a iOS 8 software issue. I've been following this issue on Apple's support forums and there are literally hundreds of people experiencing the same issue.
9/23/14 at 1:07pm