I don't know how did you checked and proved UI in new version of layout, but for sure I'd like to know if you have in plans enabling horizontal navigation panels in JIRA and Confluence.
Left vertical navigation steal useful space on the screen. Hiding pannel does not help because icons are not self descriptive. In JIRA instead of hovering on navigation elements now I have to click on them in order to see Dashboards for example.
Please advise if you will get back top horizontal navigation?