Ranked in these QuestionsQuestion Ranking
Pro Great code completion
Pro Lots of keyboard shortcuts
Pro Great git interface
Has a built-in git client.
Pro Excellent database support
Supports a wide variety of databases. Even MsSQL and Mongo.
Pro Very good extensibility
The IDEA/RubyMine ecosystem provides a lot of plugins.
Pro Great automated testing integration
Configure it to use whatever is your preferred test framework and easily run all tests from directory or file or individual tests, with run buttons in the margin. Test outputs link directly to the lines of code you need to work on.
Pro Intelligent Code Navigation feaatures
Single keystroke to code for an object, find uses of object code, rails model-controller-view, and more.
Pro IdeaVIM plugin adds Vim-like bindings
IdeaVIM plugin is available here.
Con Sometimes slow
On large projects, performance can be an issue
The price tag makes this unattractive for learners or hobbyists.
Con Constantly Indexing on large projects (even after invalidating caches)
I love this product and have been a supporter for 4 years, but performance on large projects is now a deal breaker :(