As far as languages go, I don't find there to be much benefit to one versus the other. However, and it a big however when used here, the user base for PHP is incredible. In addition to a great user base, PHP has a lot of other things going for it:
mod_rewrite seems to freak out when you use an Apache Directory directive, where it maps the %{REQUEST_URI} all the way back to the root of the filesystem. I've also noticed similar unexpeced behaviour in Apache when it uses the mod_vhost_alias VirtualDocumentRoot variable, the php $_SERVER['DOCUMENT_ROOT'] variable doesn't include the virtual host hostname. Ugh. I guess mod_rewrite and wildcard Directory directives do not work.