> On an unrelated note, I really don't understand, why iOS 9 (actually iOS 7+) is so slow on iPhone 4S. Perhaps it's the memory requirements. The 4S had 512MB

> On an unrelated note, I really don't understand, why iOS 9 (actually iOS 7+) is so slow on iPhone 4S. Perhaps it's the memory requirements. The 4S had 512MB RAM, the 6S has 2GB (plain 6/plus have 1GB).