Have you ever seen the chaos created by a group of zebras trying to cross a river at the same place and all at once? or when a group of teenagers flock to a burger joint and the staff begins to struggle to deliver all the orders? Exactly the same thing happens within Apple's servers during an iOS update. The solution for this type of issue is a simple one: acknowledge the issue and do the update later.
Due to the #iPhone and iPad's success and the way #Apple advertises their new iOS, everyone knows exactly when it will be released. However, one has to remember that the iOS update becomes available to a great number of countries at the same time! Apple knows this can originate issues and it makes their servers ready to answer a huge amount of traffic. However, when everyone wants something at the same time, some pushing and "elbow fighting" will likely happen...
Think about it, do you really need to get the new iOS right after it flows out of Apple's 'pearly gates'? If one doesn't care about the hype and is patient enough, you can quickly get it a week later and probably with an update error already solved by Apple!
If you have an old device, you really shouldn't rush into the update. The Apple #community is a vocal one, and a couple of days later you will also find whether the new iOS update makes an old device behave worse than it did before the update. With this valuable #information you can decide for yourself if you should update your Apple device.
Nowadays, Apple is making a better job in adjusting the new iOS to all the compatible devices, but we shouldn't be fooled into thinking that it will feel the same way on an old #device like it does on a powerful new one.