I think I would disagree with the notion that a woman gives better blow jobs. There are a few women that do love giving head, but knowing how most woman's brains are wired, their enthusiasm is more related to how pleased the man is. They pay very close attention to reaction and watch the man.
A guy on the other hand, first off is sucking a dick. If anyone thinks this isn't the most terrifying step we take in our life, think again. I thought about doing it from a very young age but never thought I'd ever actually DO it. The risk you are undertaking is monumental, and this one simple act can completely alter your life. Point is, if he's there sucking your dick, believe me... he is enjoying it and he really wants to be there. And THAT my friend, is what makes a great blowjob.