Once you switch to iOS 7 from a previous version, you're in for a shock: It looks really, really different, and some apps -- Photos, especially -- work very differently than before. It took me about a month to make the mental adjustment to iOS 7, but now iOS 6 feels passé. Once you get past the user-interface adjustment, you should start seeing some very useful new capabilities.
There are a couple dozen new features worth your while, including automatic app updates, shared browser links in Safari, and more detailed feedback from Siri (which can now be male or female). Here, I've picked the most compelling ones. (For the full details on what's new, check out my "iOS 7: The 'Just What You Need' Book.")