My iPhone 6+ has shown more bugs in 2 weeks than the three iPhones I had prior to that (the original, 3G, and 4). Has hard locked at least half a dozen times, particularly when receiving calls.
If you told me a month ago that Apple's flagship OS would be less stable than a heavily patched AOSP build [0] maintained by a few part-time indie ROM devs I would have laughed in your face.
[0] International GS3 never got an official Android 4.4 release. So it runs with a lot of 4.3 code, including drivers and radios, forward ported to 4.4, all held together with parts of other Samsung device code releases.
Also don't even get me started on the orientation confusion (in app - clicking back to the home screen is fine) and general lagginess and freezing on 8.0.2 on a €999 phone that's a week old.
It feels like it's missing even some of the most basic QA.