I like the article, but the fat, fixed header is killing an otherwise great design. Making the header absolute (not stick to the top of the window) would leave more vertical screen space for the crisp graphics and typeface.
I agree 100%. Also, the page down key doesn't work correctly anymore: It scrolls too much. For me, the lacking page-down-usability is enough that I would never even consider placing a fixed bar on top or bottom.
While the typography is big and wonderful, it was extremely difficult — nearly impossible, even — to read this on a mobile phone.