1. Performance on iPhone 4S and iPad 2 is Terrible
When Apple upgrades its OS, users often notice that their devices don’t function at the same level of performance they used to, especially if they are running older hardware. Apple noticeably optimizes its OS for its current devices with more advanced hardware specifications, including features that were meant to be run on the newer units. Older devices are still updated with iOS 8, but Apple isn’t as concerned about optimizing their performance for older hardware.