I do mainly iOS development, fulltime for about 4y. Before that, I developed Android, mostly in Eclipse; so I know both worlds. And before Swift I actually preferred AppCode to XCode, which is also based on IntelliJ. XCode is stuck in the nineties, while IntelliJ is such a beast, functionality-wise. Sure, it's less snappy and the font rendering is bad, but if you can live with that, it will make you a better developer. You will start "intent driven" development, where you define algorithms with method placeholders first and only afterwards declare the methods. Your classes and vars will have better names because renaming is a joy instead of being a shot in the knee. You will get a better grasp of the architecture by looking at call hierarchies. You will never again miss an instance of a renamed method in some selector, because searching for references in AppCode is perfect.
And you get all this with Android Studio, too. Let's not forget Kotlin, which might not even exist without JetBrains' involvement in Android Studio.
BTW I sometimes fell back to XCode even when I was a heavy AppCode user, e.g. when the battery was running low. Switching is mostly seamless, because both watch the filesystem and seldomly complain about clashes. Perhaps one could use some lightweight Java editor alongside Android Studio, too?