From their page:
"Super Speedy Search brings fast and relevant search results to your users and your oft-forgotten site admins. Don’t pull your hair out with basic search, which matches too many things and doesn’t sort them properly.
Our search weights are fully customizable, and we even have our own custom-coded ajax handler to bring ULTRA-fast ajax to your WordPress website."
Would be great if someone had this, I'm a performance freak.