When I updated my iPhone 5 from 6.1.2 to 7.1.2 I was really pissed at how clunky it got. Animations were no longer liquid smooth and there was jitters everywhere. I have an iPhone 5S now and am on 7.1.2. I'm thinking of updating to iOS 8 to be compatible with the iPad Air 2 I'm getting (I want that text from iPad feature). Has anyone noticed ANY performance issues on the 5S on iOS 8?