A better approach
We knew this could be much better, our target was to get the filtered results to show in. Obviously you can't load a new page and reliably get the results to appear in under 1 second, too many factors are against you. So, we looked at a client side solution.
A really important part of this site is SEO friendly URLs, luckily the HTML5 history api is widely supported, this made the challenge a lot easier for us to tackle. Every time a user clicks a filter we could just push a new state to the browsers history, this keeps the same behavior which we loved before, but without a page refresh.