Given that the iPhone 5s is about to start getting it's sixth year of OS and security updates, and improved performance for older devices was the headline featu

Given that the iPhone 5s is about to start getting it's sixth year of OS and security updates, and improved performance for older devices was the headline feature for this year's iOS update,I'd say that the assertion is already proven. Especially if you contrast with the "maybe you'll get two years of updates" experience provided by the majority of Android device vendors.