How efficient is OOP in PHP5?

Hi all, I have heard that "function style is 400% faster than OOP in PHP", and give a little agreement. So in the past year, I write more PHP code in function way while less in OOP way. This morning, I read an article called "How efficient is OOP in PHP" according to the author's test, writing PHP code in procedural way(functions) is 200%+ faster than OOP way. But this article is written in 2003, now, I am using PHP5, how about the performance of OOP in PHP5? Could any one give me more efficient references? Any suggestion or help will be greatly appreciated. Qin Jianxiang