I am going to start tracking Synapse and other matrix.org apps, because they are doing some neat stuff, and I am going to start participating in that federated network. 
I recently replaced my phone, and am no longer using Signal (it is tied to Google in a couple ways), so Matrix has certain advantages over that, and with this release it is noted:
Support for using phone numbers as 3rd party identifiers as well as email addresses! This is huge: letting you discover other users on Matrix based on whether they’ve linked their phone number to their matrix account, and letting you log in using your phone number as your identifier if you so desire. Users of systems like WhatsApp should find this both familiar and useful
I got on the IRC bridge and asked them about certificates and was pleased to hear:
For TLS certificates, you can use a self-signed certificate for federation, and a LE certificate for client connections. Client connections would connect to matrix.example.com, so you can do the LE request on the same server as where you’re running your Matrix server.
That solves a problem I had with my jabber server, where I wasn’t able to use the same Let’s Encrypt cert for both my main site and the jabber server, even though the server is redirected via SRV records (Matrix can also use SRV in this way).
Look forward to a lot more Matrix posts, and not just about the prequel movie being made!