I wasn't able to use Xcode 9 earlier (had to submit apps), but now have the GM. While I love the speed of the new editor and all the scrolling bugs it fixed, there are numerous issues:
- Dragging in source to the project from Finder brings up the familiar sheet that you can configure what targets to add to. Files are added, but they end up not being in any target. I always need to bring up the file property inspector and change target membership there. Annoying!
- Multiple tabs in Xcode cause a serious performance hit when loading projects. I use multiple tabs to quickly switch between configured workspaces specific for storyboards, source, test results, etc.
- Xcode often gets stuck in 'Indexing | Prebuilding...' Have to force quit.
- Few crashes earlier when setting slice information on image assets.
- Setting custom view subclasses in the storyboard often leaves the 'inherited from module' checkbox unchecked. Running the app then gives you 'Unknown class in Interface Builder file'. This is kinda tied to the first bug above in that it seems one has to manually check checkboxes after doing some task.
So I'm very tempted to revert back to Xcode 8.3.3. Which unfortunately doesn't give my the iPhone X simulator or ability to move to Swift 4. My apps do run seamlessly on the iPhone X simulator though. And Swift 4 migration was quite easy, so I could do that again in the future.
Anyone else struggling with Xcode 9 like this? Personally, I don't see this as ready for prime time and would definitely not submit any of my apps with it at this time.