Since the arrival of iOS 9 I've noticed more than my fair share of 'bugs' that plague the platform - on my devices at least.
As it stands I have an ongoing problem with my iPad Air 2 which causes it to soft reset on a regular basis. As it stands the latest iOS 9 release has not resolved the problem. I'm pretty sure that the problem is iOS 9 related, as it first manifested the day that I upgraded. Prior to upgrading to iOS9 my iPad had 100% rock solid reliability.
I have two iPhones at the moment, and both are exhibiting an annoying, if much less drastic problem. Notifications will get stuck in the notification panel and it's impossible to clear them. The best fix appears to be a restart. For now I prefer to work around them and then restart the phone to clear once a day.
Given that Apple has built its reputation on the promise of reliability these aren't the sorts of problems that should be making their way through into released software builds.
Again its worth pointing out that as Apple has such a small set of devices to support, all of which are its own products, problems like this aren't acceptable.