PHPStorm is more focused and coherent and includes some features that IDEA + PHP plugin doesn't, IMO. If I were a full-time PHP developer, I'd use PHPStorm, but for my occasional PHP needs, IDEA + PHP plugin is ideal.
PyCharm is much the same - for full-time Python development, I'd prefer it to IDEA + plugin.
It has plugins for:
* ASP * Behat * CoffeeScript * Gherkin * HAML * Markdown * LESS * YAML * NodeJS * Dart * AngularJS * C/C++ * Mongo * Apache/Nginx * and a lot more ...
Yeah, I'd say it's full-fledged.