It should come with a warning that its gonna peg a cpu on my macbook with firefox. Google is my homepage. I don't expect to lose half my battery by opening firefox and stepping away for 20 minutes.
It's very fast for me on Chrome for Windows but the fan kicked in as soon as I opened the page. Looking at the Chrome task manager it's using a huge proportion of the CPU compared to other tabs.
I've tried gadgets like this many times (though nothing as cool as that buckyball) and it's been my experience every time. It's slow because it's just HTML and CSS.