1) Does ElasticSearch offer wildcard or phrase-based searches, or is that a limitation imposted by XenForo?
2) Does the ElasticSearch configuration allow for custom stopword lists and minimum search word length?
3) Does ElasticSearch return results based on relevance?
4) What type of resources does a server need? We already have a dedicated box. Sphinx runs almost effortlessly even when our vB installation bogs things down, and the index is a manage size given that we have 7.5+ million posts and 800+ online in peak hours.
5) With Sphinx, I have to run delta indexing every few minutes, then do a master rebuild each night during off-peak hours. Does ElasticSearch update immediately, or do I have to run cron on the server to generate an index?
6) Is this a case where we can disable FULLTEXT indexes on our database tables?
I'm sure I will have more. We now have approval from our staff to convert our vB3.7 to XF--everyone seems to be looking forward to something newer and better! I've been fielding questions about the search in XF to see if it improves on what we have with vB and Sphinx. (And I have found that Sphinx was returning better results than vB's own built-in search.)