Do you guys rely on the editor to build you levels and position your objects, or do you rely completely on code? I tried to use the editor in my current game especially to try the new features like the action timeline or reference, but found it to be a little confusing linking the stuff I create visually to code.
Editor vs Code
All code. I don't need another layer of bugs between me and a working game. It was painful using the editors last time I tried.
If you have a sophisticated scene using the editor will save you hours of time. Putting coordinates into the code may be really painful and time-consuming. Thus editors.
Do a mix of both, layout and positioning in the sks editor, then do everything else in code. Keep you actions in code, the action editor is a good idea but its a pain to work with. Also don't bother with XCAssets, just stick everything in good old *.atlas folders.
Excuse me, what's so good about *.altas folders?
If you are using images on your sprites that have an animated embeded alpha (that does not fill the image) using XCAssets resizes the alpha and the rgb to "fit" the image bounds. Using the same images in a *.atlas works fine.
I currently use the editor with most of the new features(reference node, actions, reference actions, Camera Node). There are some issues with it but nothing which stopped me from using that approach.
If you didn't see the WDC video yet(What's new in SpriteKit) I can suggest to take a look at it, it shows how to use some of the features. Also the demo project from Apple(DemoBots) shows how everything fits together.
I've built my own OSX editor for my SpriteKit project. I have some specific needs for managing large and complex areas and scenes, as well as some auxiliary features like map generation and texture tile slicing, so it made sense for me.
I use the Particle editor in Xcode, but not the scene or actions editors. I was using the Actions editor, but kept seeing bad interactions with the XCAssets atlases, so I switched to doing all my animations in code, and that's solved all the problems I had with sprite stretching.