AA 2 does work properly, AA3 has a lot more setup needed. There are quite a few fixes that are in AA3 that AA2 doesn't have. (one of my biggest pet peeves was every server reset having to click on ocd vaults and set them back to the name you had it at before)
AA 3 requires a lot of config settings added (including listing every mod you have installed, on the gameusersettings.ini) The smithicator is busted and doesn't seem to have all the blueprints it should (both the smithy and fabricator portion of it). AA 2 I don't remember having that problem. Aside from bug fixes, there isn't much change. I don't understand the point of separating the mods into 7 damn files, as there was no problem with it before, if anything, it makes server load times a lot longer, as you are adding in 7 mods, as opposed to 1. Dicossion board is also dead on AA3, AA2 has a fan base that has been answering questions and they haven't stopped. AA 3, the developer flat out stated he wasn't going to answer anything on steam anymore, and want you to join his stupid discord (it's a family like bs discord, with aa as a side note on the whole thing, and responses are still slow there) so people haven't been posting to it.

AA2 = 1 mod to download, no more updates, a few bug fixes missing, better community of people that help, easy set up and go.
AA3 = 7 or 8? mods to download, kinda updated (I'm pretty sure AA is just dying), a few bug fixes, no community unless you jump on a personal discord which is just pointless, tons of configs you have to alter and add information to, before you can even get it to work.

There's probably quite a bit to add, but can't think of it right now.

If anyone else could add more please do, but as I said before it's pretty dead on the discussion board (which is shouldn't be)