Earlier quoted context omitted.
I'm an outsider fan. I've attempted to use IntelliJ on multiple occasions, but it just can't really compete with Eclipse as far as my requirements are concerned. But the competition from and innovation in IntelliJ has no doubt made Eclipse better (and modern Eclipse is kind of awesome and just keeps getting better).
What is it about your requirements that means that IntelliJ can't compete with Eclipse?
I almost never close a project and I never open a project. It's just all there. If I need to use or modify a piece of code, written by me or someone else, it's all accessible to me at all times with a single keystroke.
No project switching. Close to no context switching. IntelliJ doesn't even come close to this kind of power.