I've tried Firefox, Safari, and Chrome. And in every single one of them, scrolling works fine with spacebar, with the mouse, with Page up/Page down, and even that vim*-extension's 'd'.

I also enjoyed the effect. For anything I visit repeatedly, such as webmail or github, or news websites, I prefer a "lean" implementation. But a product page that I will visit may twice in its lifetime? Knock yourself out!