Heard good about Diaspora but never seen ... anyone link to their profile, just say they like their website policy or company idea so not sure how 'sociable' it is. Amino is quite popular but it is mostly connected to message boards as far as I seen (it confuses me and I have to understand it for marketing ugh...).
Believe me when I tell this: Diaspora is dead. It is an old project, which just accidentelly got some press in around 2010 when it was founded, because it gained its funding goal back then on Kickstarter really fast, and Kickstarter back then was all new and that's what the buzz went all about.
It was being written back then in the hype of the month thingie back then, so Ruby on Rails, MongoDB, a pain to install, nobody used it back then, almost nobody uses it today, it's still being developed though but a niche product, nothing more. Friendica is far more easier installed and progressed than Diaspora, but also most just use it as some kind of connect to other networks thingie, and that's it. Not that it is a bad project at all, it isn't.
The only development of the last few years, which really gained some momentum was an opensource Twitter clone called
Mastodon. Althouth not as big as Twitter, the estimated userbase is still around 1-2 millions, which is not too bad for it being two years old.