Gregory's Server@AudraTran SimpleX also has dreadfully slow speeds if you're in more than a couple groups, it's developed by a for-profit company and like 95% of the servers are run by them.
It's tech to watch and does a lot of cool stuff, but I firmly believe it's far (as in VERY far) from being a viable alternative. I'd go for Session before I'd go for SimpleX, at least for now.
Yeah I mean they both have pros and cons. The point is SimpleX understands anonymity is as important as privacy, and serves as a good example of how to do it. Signal clearly does not think it's important.