We've loved algolia for the 2-3 sites we've used it for. The speed is unbeatable.
I wish we could've used it for one of our HIPAA use cases (patient data). I could've rolled out powerful search for an internal site in a day, but instead I'm having to build in postgres full text search and looking longingly at them.
I wish some more effort would be put into Postgres full text search seems to have stagnated somewhat, it does a lot but is also lacking compared to say Lucene.
Not that its going to be as good as Algolia but it could be a whole lot better for many use cases specifically TF/IDF and BM25 scoring: