The Growth of Lucene

All of a sudden I’m seeing Lucene (and Nutch and Solr) being adopted by a bunch of my companies.  While several have been using it for a while, it’s spreading rapidly.  I’m curious about the experience folks have had with it – everyone I’ve talked to is thrilled; I’ve yet to hear from someone that said “it didn’t work for me and I decided to use ‘X’ instead.”  Any feedback?