Great module that I've used many times so far. Performance is decent too.
I have barely scratched the surface of the functionality: the module assignes relevance scores to each found document and provides the regex for the matching term so you could highlight matching text in your document.
The module also provides search patterns to make the search more specific; for example you can search for "word1 AND (word2 OR word3) AND NOT word4"
Reviewer ديم الخمير wrote about a problem in this module in his/her review, however he/she was simply not using a method correctly.
Among the three available indexing modules this one offers the best balance in the form of a simple and effective API and a good search description language. Indexing a few thousands documents is fast.
Unfortunately there is a little point that make the module less worth than it could.
Removing document when the 'positions' argument is 0 and you don't have the original document keeps references to the document in the index database. That is, if you add a document and then remove it, a search would still return the removed document id. This is very wrong! (RT #43508)
You can work around the problem by checking that the document id exist.