A few observations:
Mastodon: Hard to install, very resource intensive, very opinionated (i.e. over asinine things like character limits).
Pleroma: Poor usability. More functional.
Misskey: Sort of okay. It has some interesting features and the usability looks alright? The way it handles visibility is different than other systems leading to unpredictable results.
I have to look deeper into this implementation.
Every time I hear of them, it has to do with, ironically, complaining about NSFW content on the fediverse (is it really that surprising that someone will use it for this?).
I also have potential concerns about language / cultural barriers here.
Go To Social: From what I've seen of it in the wild, it behaves unpredictably on the fediverse and is very buggy in federation.
It also throws out Go's potential performance advantages by just using it as another tool for single user instances.
It also looks very alpha.
