Why bother learning the command sequences of the Vim editor for your PHP development? In a word: speed, as any experienced Vim user will attest. Because Vim is a modal editor, you use meta keys to control its behavior. This may take some practice to get used to, but it's precisely this feature that allows you to write code and navigate the editor's features with incredible speed.
For those PHP developers who haven't tried Vim, Jason Gilmore has written a PHPBuilder article to help you begin using Vim for PHP development. He writes:
When you choose a streamlined IDE [such as Vim], you forfeit the visual bells and whistles usually found in many commercial products but you gain the ability to write, organize and refactor code as quickly as you can type.
After you installed Vim, you can follow along as the article walks you through creating a simple PHP script using Vim.