sávoy@earthling I use both but prefer XMPP overall as I run my own personal server for me and my wife. If you're self-hosting, prefer a lighter setup, or don't need something like Discord, I'd say XMPP.
Matrix is more of a pain if self-hosted but has more centralized features (especially with the "official" Electron client) compared to XMPP.
As for client recs:
XMPP - Conversations (Android) and maybe either Gajim or Dino for desktop.
Matrix - Riot or Nheko
All Jonkman Microblog content and data are available under the