Our client is sailboatowners.com which offer resources, discussions, spare parts for sail boats. The discussions is a very important part of the website because members discuss issues, fixes and troubleshoot faced issues with boats.
The forum is based on vBulletin. It was using default mysql search. There were many issues with the search including performance and accuracy issues. Client reached to us for having better search. We implemented Sphinx Search for the forum. This resolved the issues with performance of the search and accuracy issues. You can see search in action here