I also think of faceted search of having the counts and narrowing the options as you drill down.
Ironically enough that was through Endeca which was introduced to my company (at great expense) as I was pushing for solr. Eventually solr became the tool of choice because it was more flexible and less cumbersome.
I recently completed an Endeca to Algolia migration. I spent quite a bit of time auditing the Endeca implementation, from the XML files to the Windows desktop application. It was pretty good for its era.
While the acquisition was good for me financially, I agree that Oracle didn't really invest in sustaining Endeca as a product. I am proud of what we achieved at Endeca, but search has come a long way since then.
Ironically enough that was through Endeca which was introduced to my company (at great expense) as I was pushing for solr. Eventually solr became the tool of choice because it was more flexible and less cumbersome.