If you're like me and have dozens of tabs open at any given time, you'll like that you can now hover over a tab to see a preview of what's there. Plus, Safari now shows favicons in the tabs, so it's much easier to find the tab you're hunting for.
If you encounter a web page in another language, now you can use Siri's built-in translator to turn it into one of seven languages. Just go up to the menus at the top of the screen and click View > Translate > Translate to English.