XFES 1.0.1 fixes several bugs:
Prevents error when rebuilding search index if per page > 2500
Extends the timeout when talking to elasticsearch to support long running operations better
And provides several improvments:
The current stemming configuration is shown on the elasticsearch setup page.
The stemming language can now be chosen (rather than only supporting English).
The elasticsearch mappings can now be optimized. Optimized mappings take up less space and should allow results to be returned more quickly.
With stemming, you should be able to get results back on various versions of words, (automatic searching of variations on a root word like date, dates, dating, etc). It has no minimum word length like the default MySQL search configuration.