This new post on the ThinkPHP blog (from Sarah Hermann) talks about some of her first experiences with the popular IDE from Zend, Zend Studio for Eclipse:

The last few days I've started working with Zend Studio for Eclipse. At first view I didn't miss anything which I've used in Zend Studio 5.5 and the IDE looks very good. [...] Overall I think Zend Studio for Eclipse is a great tool to develop PHP applications. With a large amount of plugins, Eclipse provides a platform which gives the possibilty to develop a whole application within one tool, that's a great benefit.

Most of the issues that she came across from the transition were minor things - keystrokes for shortcuts changed, slowness with the breakpoints - nothing that would stop her from dropping it and going back to the regular Zend Studio 5.5.