I set up calibre-web on my home server but didn't use it for very long. I've got my books separated into fiction, nonfiction and technical libraries and calibre-web could only handle one library database. I would have had to run multiple instances to get the different libraries served. I also still had a need to use calibre on my desktop so it was necessary to reimport the database from my desktop into calibre-web to keep things in sync. If you're going to manage everything in the web interface it might work for you. It was just kind of unnecessary for my needs.
Nice! I hadn't come across Kavita yet. I've been using CalibeWeb for years and always found it dated and clunky. I haven't tried the demo yet, but the screenshots and feature list seem like it's Jellyfin for ebooks. I'll have to spin that up and give it a go.
Looks clean and the screenshots look like it supports multiple libraries. Their demo site won't log in but I might spin it up this weekend and play with it. I still probably don't really have a use case for it. I'm always going to need calibre on the desktop. Ubooquity is another that I tried but still had the same lack of use. One of these days I might want to move to a web based solution but not really there right now.
I’m running calibre in a docker container, and have 3-4 libraries setup. I am able to access them all through the built in web service. I know it’s not the same as calibre-web but just want to point this out.
I can’t compare the reading options between the two though, having only tried the one option myself.