The main feature that I miss from CLion is the ability to refactor. In CLion you can rename a class, and all of its usages, declarations, etc. will be renamed.

The most useful thing CLion can do is change the signature of a function, and its corresponding implementation and header declarations will be changed. So, you can rename a parameter and its declaration and implementation will be renamed for you, or you can delete a parameter, or change the type of a parameter, and CLion will change all its usages/definitions/declarations for you. All of this effects across all files in your project, so if you're in a .cpp file and you change the function signature, its declaration in the corresponding .h file will change as well.

(I believe you can do all of this in Eclipse as well)

Sadly I have yet to see a vim/emacs configuration that gets anywhere near the level of Eclipse/CLion.