I am just finishing up rebuilding the search index after installing the new search. You benefit from a very small stopword list and no minimum word length, allowing nearly any search to return meaningful results. XFES also provides support for returning results based on how relevant they are to your search. You can select relevancy ordering on the advanced search page. XFES also allows for a "stemming analyzer", which means that words are reduced to their roots before searches are performed. For example, a search for "tests", will automatically return results for "test", "tested", "testing", and similar words.
