The problem I had was that the entire experience became really slow when I had it all working together as one "response". Sending back all that HTML for an entire form with some large select lists as well as the response of results became noticeable laggy when there was more than a half dozen results.
I ended up switching to Alpine Ajax (https://alpine-ajax.js.org/) and pulled the form out of the response and just used a local x-data on it to track the state. This greatly reduced the HTML I needed to send back to just the list of results. I did make the form a bit more complicated but the experience felt a lot snappier. Both versions just synced the form state from the URL and kept the initial render as full HTML from the server.
I found that Alpine + Alpine Ajax was SMALLER than HTMX 4 even though (in my opinion) it offers a lot more features in a more approachable and intuitive way if you need to do interactivity and don’t want to trigger a request just to toggle some classes or attributes. Of course you can use both together (I started down that road) but you are mixing worlds and making the bundle size bigger at the same time.
I still like HTMX and will probably use it again. I just found that with an interactive experience like a product listing page, where the HTML response was quite large/expensive to fetch, it wasn’t the best choice for that.