It just works. I spent years with Eclipse (but quite some time ago now), and it was always a pain getting particular things to work properly. The last time I messed with it was doing research for an article I was writing. I was try to get Gradle support enabled. I wasn't able to do it, but I admit I gave up pretty quickly because I don't have the patience for messing with tools that don't work any more.

In truth, I really liked the Open aspect of Eclipse and I wish it work better than Intellij. Maybe it does now - I don't know. For Java Intellij is awesome, and does everything you could ever dream for. For Kotlin - well Kotlin is an Intellij product and the support for it is awesome.