Any other major forum operators uses Sphinx Search here? It's powering Elliquiy right now, and I couldn't be happier with it. It will be powering Blue Moon before long as phpBB's searches and keyword insertions are currently responsible for most of my non-reindexing slow queries. The index size is a bit smaller than SMF's hashed inverted index - but larger than MySQL's native fulltext index. It's still hashed, and since it runs an actual search engine daemon, with none of MySQL's cruft, it's faster than SMF's and you can forget about fulltext trying to compete. It also supports stemming, delta indexes, and you can even weight the results according to your preferences. Also, personally, I find FULLTEXT's stopword filter to be annoying. : ) Go ahead! Search for 'at' on Elliquiy.