How much better is Apache Solr than its non-Java competition? Is it so much better than other solutions, e.g. this one (Sphinx with PHP API) or Zend_Search_Lucene that it would be worth suggesting that a client move to a different hosting provider than the one they are working with now? The current host does not support Java.
If there are other decent solutions for indexed database search which are more palatable to typical web hosts, I'd like to hear about them.
It is A Big Deal for them to change hosting providers, so I would like to know if the move would be justified.