RubyMine is my IDE of choice because no other IDE exists that is designed to be as powerful & specific to development in Ruby on Rails. Plus, it supports all the other languages as well, & with a full license you get access to the other language suites by Jetbrains.
As far as features, it has a full-featured debugger that synchronizes with the browser when running a rails server. The "Tool Windows" for Version Control & the Docker Add-On are also frequently used by me, and they're amazing. I have several code snippets and live templates that I use, Emmet plugin, the list goes on. It has every feature you can imagine with a stack of great plugins that are all very evolved since they're not just for RubyMine, but all of JetBrains suite of software.
If you are a Rails or Ruby developer, you absolutely must use this to make your development faster.
This is a great decision, Patrick! How long have you been using RubyMine? Also what IDE did you use before?
Before RubyMine I was using Atom. I thought Atom was the best option... Then I was hired on a development team that used RubyMine. That's when I could see that RubyMine was much more stable and full of features than Atom (or even Visual Studio Code).
Those other IDEs were (at least at the time) a big mash of half-working third-party plugins and lacked that unified ecosystem you get with JetBrains.