Really? It went perfectly smooth for me and about 7 of my close friends. In fact we all were just talking about how smooth and fast the updating went this time...
In fact amazingly smooth. The downloading and install took a good 20 minutes to complete. Not bad for something free.
What does surprise me however is how many changes their actually is in iOS 9. It's VERY different and has a TON of changes all over it. And that's without my TWO ordered 6s and 6+s... Can't wait.
There's an inherent downside to Apple public releases of software. Always some bug on day one which no one caught somehow. The quality control is on the decline. I'm a huge Apple fan and will always be but they are definitely letting their QC slip on software. They shouldn't tie X.0 updates to new iPhones. Seems like they can never hit the deadline without a significant bug. Look at watchOS2. Still a mystery. Last year's 8.0 release where cell data wouldn't work at all haha. It's obvious they need a lot more help with their mobile software now as this was the first year they've done a public beta for iOS. Also, I think there needs to be some clean up of underlying code if one must restore a phone as new or perform clean installs of updates. Should "just work" but in many cases it doesn't.