The Eclipse PDT, in my eyes, doesn't really compare to Zend IDE 6 (Neon), Komodo IDE, NuSphere PhpED, PHPDesigner, etc. The main reason is because all of the latter are IDEs and the PDT is not, it's more of a syntax highlighter for an IDE (Eclipse). Now, Neon is based on Eclipse and uses the PDT base, but it extends it so much further it's not even funny.