Generally a big fan of HA, been using it for ~8 years. They've done a lot to make it as user-friendly as possible. Running your own HA server is not for the faint of heart though, even though they've made the installation and maintenance process as streamlined as they can. Because the choices for running it are pretty limited and all have tradeoffs:
* Docker container (can't use add-ons)
* VM running their OS (you need to know how to operate a VM and deal with issues like passing through USB hardware)
* Install their own OS directly onto a box (can't use it for other stuff, limited by the OS)
I've been running it on a VM over the years variously on a Raspberry Pi, on a Mac Mini with Ubuntu installed on it, and most recently a UGREEN NAS. When it works it works great, but when something breaks - and it inevitably does - then God help you if you aren't some kind of Linux wizard. The error messages tend to be unhelpful (if you can even find a way to view them), and half the time I can't even easily figure out if the problem is on the side of the VM or the host.
Also if you're trying to do anything at all unorthodox or on the fringes of what's supported out-of-the-box, you're going down a rabbit hole of debugging YAML and JSON messages and whatever arcane thing you do is something you're going to have to relearn from scratch when it breaks in a year.
Anyway, overall I think it's an excellent product, but you should be prepared to be your own IT staff if you're thinking of using it.