I used to keep up to date on my IntelliJ, Rubymine, and PyCharm licenses. Rubymine and PyCharm are lighter weight.

It is mostly to save money, but now I only keep IntelliJ up to date and install the relevant Ruby and Python plugins. I also stopped using the separate free Android version of IntelliJ and have the Android plugins installed also.

I did go through my IntelliJ settings and removed all the plugins that I don't use - something I recommend.

Does an up to date IntelliJ offer the same full set of functionality as PyCharm? As in, is PyCharm just IntelliJ minus some stuff, or does it have features IntelliJ doesn't have?

I think that it does.