There are many days when I log into JIRA and there are navigational changes that are not enhancements in my opinion. In addition, there is no information on how to maintain some of the functionality of what you had before or how to do it in the new UI.
Specifically, as one example, this morning, I logged in and now I can no longer collapse the menu of items into the left side bar for easy access. Instead, the only think you can do is minimize the menu and open it back up again any time you want to navigate to other screens or reports. So now, for every navigation to a different page, there is an additional click that has to be done.
As a constant user of JIRA (in JIRA for the majority of the day), these continuous UI updates that keep happening are an impact to our business and are not helpful.