The only thing I don't like about IntelliJ vs Eclipse is unit testing. Because Eclipse eagerly compiles everything with its special compiler it seems to have a much faster startup time for unit tests. In fact with Eclipse I use JUnit as a Java repl because you can test a single method. Also I hate how I can't configure IntelliJ's gutter size. It feels massive. Other than that IntelliJ is far superior.
As for dark theme and theming Intellij/Eclipse both have their quarks (Eclipse being far more quirky).
Here is a screenshot of a personal port of the Atom One Dark theme (I love that theme) to both IntelliJ and Eclipse (left and right respectively): http://imgur.com/Myo4KxM
> Because Eclipse eagerly compiles everything with its special compiler it seems to have a much faster startup time for unit tests.
You can configure IntelliJ to behave similar, the option is disabled by default. Its the "Make project automatically" option in the "Build, Execution, Deployment -> Compiler" settings window.
Also, IntelliJ can use ejc if you like, the "Build, Execution, Deployment -> Compiler -> Java Compiler" window, the "Use compiler:" option.
I tried that before but its still faster in Eclipse by 3/4 of a second (I was wrong about being just the compiler). Its as though Eclipse doesn't fork a new Java process.
As for dark theme and theming Intellij/Eclipse both have their quarks (Eclipse being far more quirky).
Here is a screenshot of a personal port of the Atom One Dark theme (I love that theme) to both IntelliJ and Eclipse (left and right respectively): http://imgur.com/Myo4KxM
IntelliJ One Dark Theme: https://gist.github.com/agentgt/bf2271786c250e86ab19
Eclipse One Dark Theme: https://gist.github.com/agentgt/fcaf75eb8acf92e08926