I don't have long term experience with either, but I started to selfhost both of them (anonaddy and simplelogin) about a month ago

I enjoy both, and both are running well at the moment - but there is no long term experience

I think , I would normally like Addy more (interface, capabilities, etc), however honestly it was the one, which caused me a lot more problems (mails getting lost unnoticed, without any notification, even multiple times - of course, in each case it was some config setting which I wasn't fully aware of, so kind of "user error). Simplelogin is running with less issues (as far as I can tell), and it's also a great piece of software: I can't even clearly explain why I use it less

Anyways, I'm very much interested in inputs on this topic, definitely look forward to discussion in this thread

What he obviously meant, but phrased incorrectly: you can’t create new posts from Sync. You should be able to comment on existing posts, though (doing it right now)