One of the main complaints that users are encountering is that launching apps seem to be slower than usual. You might think that these users probably installed the update on older devices, but there are users with the iPhone 7/7 Plus who are encountering the issue as well, so it doesn’t necessarily seem to be a hardware performance issue.
One user writes, “Ever since I upgraded, launching apps is an absolute chore. Safari, Reddit, ESPN, Yahoo, texts [and more] all have a terrible time opening. They either crash back to home, freeze and require closing the app, or take well over a minute to load. I never had a single issue with my [iPhone] 7+ before last night.”
That being said, it isn’t surprising that new software releases tend to have some teething issues. Clearly not all iOS 11 users are affected by these problems, but it does seem to be a common complaint. Hopefully future updates to iOS 11 will address the issue, but if you’ve yet to update then maybe holding off could be a good idea. It might also explain why adoption of iOS 11 appears to be slower compared to its predecessors.