PHP is faster, better, smarter, simpler.
No seriously though... PHP compiled as an Apache module (with the zend engine of course) is in fact faster than any other scripting language out there. (at least everything I've read recently says it is)
PHP is platform-independant. This may seem pointless.. but its not. Being able to develop my sites on my win2K machine and then upload them to the Linux server without having to worry is a big plus in my books.