[jarin]

I think the point of it is that you usually don't need a full-width header, so why mess up the alignment of elements on the page by using one?

[Stormbringer]

No, the point is (or should be) that fixed width on a web page is almost always wrong. It will be either too big, or too small.

It is simply astounding the number of web pages that have poor appearance because the 'designer' never tested them on a different size monitor, or with different size fonts.