I tried this out last week, hoping it would be good enough for me to cancel my plan of setting up a matrix server.

It's a nice idea, but I likely will not continue using it or try to sell anyone I know on using it because it doesn't let me share conversations between my different devices (like my smartphone and my laptop). If someone replies to a chat I send from my phone, I want to see the reply (and the whole thread, really) on every device I have Delta Chat installed on.

So, matrix it is, I guess.