Oh I could rip. I probably spend >9 hour a day in Xcode, so it and I have gotten very intimate.
My personal favorite is the dragging of multiple images, non-vectors, into a folder in an image xcasset, then manually moving each of them to the universal 2x space (because, you know, defaulting to the 1x space when there are no devices in production is genius) only to have them revert back into the unassigned space at the very end. Doesn't always happen, but it happens every time I work with image sequence animations. Every. Damn. Time.
OR my second favorite: Completely broken subclass generation for object models. Completely broken. Two years. You knew something was odd when they never fixed the auto generated NSOrderedSet ancestors, but then Swift introduced namespacing along side the requirement de-bonding your model for extensions and that just absolutely blew sh*t up and Xcode just can't.
Then there's the smaller things, like the syntax highlighter spazzing out, then crashing, over a broken code because you haven't finished typing a for loop (fun fact, for loop is being removed from Swift in favor of for-in!). The inability to actually scroll in and out of storyboards without extreme resistance. It's non-obvious handling of errors between targets. The weird build loop locking...
But I've worked with worse. It just sucks that they provide such intense tools that can be phenomenal when they work, but hinder development when they don't. If I were to rate it, I'd give it a 2.5 out of 5.
