Try any of the examples listed on the landing page. You can easily access the HN/Algolia search equivalent by clicking on "Try Hacker News search instead" to the right (on desktop).
Keyword searches on the Algolia engine will generally result in better recall -- at least when identifying the right keyword is easy, e.g. the name of a company. They likely will require more sifting through results & keyword "engineering" however.
In my mind the two approaches are complementary. I suppose there's an argument for working more directly towards blending them :)
Trying the examples now, semantic search usually works better. But if I trim extra phrasing (e.g. how do diffusion models work -> diffusion models) they're about the same (but Algolia is much faster).
