DocSearch is great and I especially like the expanded preview that shows up in the new version.
Shameless plug: for when you get to a point where Algolia becomes too expensive, take a look at Typesense which is an open source alternative to Algolia: https://github.com/typesense/typesense
Has an integration with InstantSearch as well: https://github.com/typesense/typesense-instantsearch-adapter
