I haven't used it much. (don't use it for work) But I'll say its different. Very "backend first", so there's a bit of setup required server-side, setting up end-points and such. But not having to manage state or unpack json in the frontend is probably the best thing about HTMX.

You send a request to a server from frontend, the backend responds with html and places it on the page where specified. Its much more intuitive and lower mental load than something like react or vue.