Quickly rename classes, methods, and variables used across multiple files in the project.

Allows users to manage their repositories directly from the IDE with a GUI which lets you do all Git commands.

The database tab, while not perfect, provides all the tools you need for daily usage. You always have your DB overview on the side (you can hide it when not needed).

Supports Symfony2 (including Twig and Doctrine), Yii frameworks, and Laravel.

Has built in support for Xdebug including remote debugging.

PhpStorm has two types of autocompletion: structural completion and word expansion.

Structural autocompletion makes predictions based on its understanding of PHP, while the latter tries to predict the word currently being typed based on previously typed words. Word expansion also works in comments and docstrings and it's similar to vim's omnicompletion.

Both types of autocompletion work extremely well, have little to no problems and are quite fast even when loading suggestions on the go.

Lots of plugins from JetBrains and the community are available, from useful things like support for Docker, Vagrant, Angular, Vue.js and more useless (but fun) like a nyan cat progress bar.