Has anybody been using iOS 9.0.x on a 5s? I have seen some YouTube videos comparing 8.4 to 9.0 side by side and everything seemed to be more sluggish.. Opening apps, app switching, menus, etc. Except Siri, which was way faster. I'm reluctant to upgrade to iOS 9 and losing that snappy fast feel that I love on my 5s.
OS X 10.11 on the other hand made my 2008 MacBook noticeable snappier for tasks like safari and image resizing in Preview.