Forum Moderators: open
<h1>Widgets</h1> says "This entire page is about widgets", so this is an important page for someone looking for widgets.
<h6>Widgets</h6> says "This sub-sub-sub...section buried deep in my page is about widgets". So OK, this page does contain stuff about widgets, but not as its main subject.
A related thought is the <h1> can be rendered too big, unless formatted in CSS. I know that making <h1> look like normal text could be considered spam, but what about making it a bit smaller, changing color/font, etc.? Can that go against SE guidelines?
But the article was about the way I do it. By all means choose other ways.