I use this a lot, and it really does work. It renders everything, and renders it well. The one thing that doesn't work is maps – just too many vectors, and Javascript/Canvas/etc just can't keep up. Otherwise I'm very happy and don't feel nearly as much resentment towards PDFs as I used to.
Have we reached the point where Adobe Reader is so resource-guzzling that people prefer a JavaScript (gasp!) PDF interpreter to Reader? Wow.