Objective C projects, if that matters, but several useful editing features were removed, but the biggest issues relate to Storyboards. Action buttons were moved all around. Not sure why it was changed, as the new layout is not intuitive at all. Loading of storyboards is amazingly slow. It's been getting worse for several revisions, but it is really bad now.
Connecting from the storyboard to code is non functional with this revision. Connections have to be done from the code to the storyboard only, which means all the code has to be done before storyboard changes. This is much less efficient for coding.
Really dislike 26.4 editing changes. You are making our jobs harder, not easier.