PHP storm is the best. Fast than both of them, and have a beautiful and feature-rich GUI. I hate zend studio and eclipse, because they are slow and stupid. when you want to import project you need to cut the code outside your webroot and re-import again, WTF. IDEs like netBeans and PhpStorm could scan your webroot and auto import the project you need, much more convenience right? eclipse is too old, but his successors are growing very well. so let us just bury it with respect.
Plus, Alexander wrote a wiki article about how to config PhpStorm for Yii developing. the IDE originally support Yii and Symfony integration. And Yii team support a PhpStorm plugin called Yiistorm for better code suggestion as well. In a word, it is good for Yii developing.
plus+, you can use back your coding habit, so that you can use your shortcut setting for vim for PhpStorm. For example, i used to code java on NetBeans, i like the Alt+Shift+F (formatting code). i config PhpStorm and let it use netbeans shortcut config it performed exactly the same as what i expected.
The best thing of using PhpStorm is when you are contributing your code for open-source project, you can apply for free open-source license. Wish you have a better developing life, cheers.
I initially used Eclipse, it was pretty good until I updated my Ubuntu OS when the Eclipse didn’t work properly so I used Netbeans since. For me I will suggest that you will use Netbeans it has awesome functions and also supports Yii.