It's funny how many Windows users seem to think the PDF format is intrinsically slow, and all because of Acrobat Reader. Safari on OS X renders a PDF just as quickly as any other webpage, and always has.
I imagine if you were to test that then the PDF rendering would actually be significantly faster than HTML, since OS X's rendering is all PostScript under the covers.
Have no fear, the Chrome PDF plugin has brought all that slowness back. Joy.
So does Chrome on Windows. Why so much love for Windows users?