As someone who's pretty naive about EDA software, how does this compare to KiCad or Eagle?
Same question -- I've been using Kicad on personal and light-duty professional projects for about 5 years (yeah, Altium is the real deal, but when you're making a small run of prototypes for a university lab, sometimes you use the tools you have). It definitely has some rough edges, but it's also got a very established ecosystem, so I feel like Horizon will have to be a massive improvement to compete.
Horizon misses nothing (for me) now and has a beautifully efficent UX compared to Eagle and KiCAD. Their library concept is also well thought through, so I don't have the feeling I am wasting my time when I am contributing parts.
The downsides are:
- you still have to create many parts yourself (but parts, packages, etc are json and generating them can help a lot)
- horizon supports only newer OpenGL versions, so if your machine is old it might not run
Other than that I'd take it over all the others every day (and I do).