Also Chrome on OSX, scrolling is perfect. Out of interest, because whenever these parallax sites come up a chunk of people have significant problems, what spec is your Mac?

The Mac Pro landing page is another example, a lot of people think it's amazing, but I've seen videos of that where it just doesn't work for some people - something weird is going on here as it's clear the designers + front end people aren't seeing such problems with parallax, so why are others, and is it rare or more common than expected?

I tried on my macbook + Safari and Chrome; both render perfectly smooth.

The scrolling is much smoother (and proper) for me. Win 8.1, Firefox.