Nope, you don't get everything. I don't use CLion, so I don't know what all the differences are, but for the Rust plugin, CLion gets more functionality than IntelliJ:

https://github.com/intellij-rust/intellij-rust#compatible-id...

I understand the same goes for yet a third branch, which is .Net, and possibly a fourth, which is AppCode. But I don't have any contact with those ecosystems, so don't really know.

When did that happen? For a long time you couldn't, say, install the "CLion module" in IntellJ - it simply didn't exist in their plugin repos.

That and you can use the different apps to sandbox the plugins so you aren't loading unused ones for each project!

Not with CLion.