Personally I like having separate installations for each language-specific IntelliJ flavor just to reduce confusion when toggling between different windows. The slight GUI differences also help to "code-switch" (in the linguistic and literal senses).

Actually there are some variations.

Example: Python plugin when installed in IntelliJ is missing venv integration in the terminal.

https://youtrack.jetbrains.com/issue/PY-22067

There are slight differences, I believe. IntelliJ is also a little more cumbersome, since you have to map the modules to specific languages. I do mostly just use IntelliJ with plugins these days though.

I always feel a bit silly, because I pay for their "all products" pack, but only really use IntelliJ, because I bought it before realizing the plugins really were 99% the same as the specialized IDEs in most cases (CLion isn't, I think). At this point it's cheaper to just pay the ongoing renewal fee, I think.

I've heard that before but I'm skeptic about if it's exactly the same.