I really don't understand how anyone can use eclipse. When I've used it, it feels incredibly clunky compared to intellij, stuff isn't discoverable, code completion is worse, quickfixes are harder to use etc.
They are very comparable products, but it's mostly a matter of what I am used to.
After using Eclipse for ten years I feel like IntelliJ makes some actions difficult to get to, either through weird key bindings or not providing them at all. I also prefer Eclipse's code completion as it feels like IntelliJ's gets in the way at times.