I have heard from many non-techie iOS users that iOS 7 is a buggy mess. I take that to mean that everyday users see the manifestations of bugs and that the bugs are obvious and annoying.
Among the two most mature OSs, the apparent fact that iOS 7 was a buggier release than iOS 6 might be what's making Android look relatively good.
Suure, from a website called 'Crittercism', whose investors include Google Ventures. I'm usually not skeptical, but I had a weird feeling.