I've been using WebStorm (and IntelliJ IDEA) for the past couple years and love it. I have no intention of swapping to any other IDE unless I really have to. Can definitely speak to the extreme convenience of instantly finding usages/definitions, "intellisense" of func params, plugin architecture, super customizable settings, built-in language support and linting/evaluation, refactoring assistance, live templates... Just a godsend, to be frank.