I had been using PhpStorm for years now and recommend it a lot for WordPress development. Simply put WordPress code base is significantly large and very convoluted. Good IDE is not just beneficial for it — it is indispensable.
PhpStorm had steadily got more and more functionality, related to specific web development projects and standards. After years of hopes, whining to product manager on twitter (hi, Mikhail!), filing issues on bug tracker, and some consulting — version 8 had shipped with dedicated support for WordPress.
This post is by no means exhaustive guide to development in PhpStorm, but it summarizes much of my experience and techniques using it for WordPress projects.