Cpluv has done the switch for its search engine from Zend Lucene to Sphinx.
It is actually a breeze to implement and work with Sphinx once you got to know how everything’s working 
When we choose the engine to be used instead of Zend Lucene, there were 2 finalist. SolR and Sphinx.
We used sphinx because of its ease to use/index and configure.
I’ll publish a small beginner tutorial tonight to help people to jump in Sphinx.
The community is great, although the forum could be better. But I know that they’re working on a new website, so it will probably be updated.
It’s definitely worth a look if you’re looking for a POWERFUL, FAST AND LIGHT search engine.