If you have a newer iOS device and you haven’t yet upgraded to iOS 11, you should know that you’re in an ever-dwindling group. Apple’s iPhone 8 (and the yet-to-be-launch iPhone X) come with iOS 11 pre-installed, but as with all iOS update rollouts, iOS 11 is also being installed on older devices at a brisk pace. The current percentage of iOS 11 users is nearly 25%, and since the update has only been available for about a week, that’s obviously an incredible feat.But what the 25% figure doesn’t fully reveal is how Apple’s mobile operating system compares to...