>Not to mention you write "obj." and can instantly see all the methods available with arguments.

Eclipse could learn a lot from Xcode on how to do autocomplete well. I haven't spent enough time thinking about each to articulate a list of differences, but overall Xcode's implementation feels much faster, more responsive, and more intelligent - in terms of both when and what to show. It's the same "feature" in both IDEs, but in Eclipse it feels like I'm fighting against it much more often than in Xcode.