Curious about what wasn't working with matrix?

Performance was never amazing even with a dedicated server for local users. We also had insane issues with pedos and traffickers joining our rooms to spam their telegram links or CSAM. It got to the point that it wasn't fun to use and Matrix never seemed to care. They claim to be tough on that type of thing but our experience didn't reflect that.

how XMPP is comparing?

More reliable which counts for a lot. Still working through some stuff with our host and messing with some add-ons for XMPP but over all everyone is happier.

I haven't used XMPP in like over a decade. Is it still about the same? Better? I don't think I was that aware of its group abilities.

I'd say it's roughly on par with most of the better known chat solutions these days if you're looking for something that's reliable but not bleeding edge. It's been working well for us, YMMV. Groups are a thing and work well and there are even bridges to Matrix and many other platforms.

How does the excryption compare? about the same if you choose the right option?

Default is blind trust OMEMO which works very well. I recommend checking it out for yourself if you aren't familiar to make sure it's appropriate for your threat model.

You got a favorite linux client?

Gajim was the early favorite and I haven't found anything compelling enough to change. I've tried probably a dozen clients total across various platforms and Gajim mostly just works. These days that counts for a lot with me.

(I know I am pestering you with too many questions, feel free to ignore)

Nothing but love here mate. Some days I have time to answer, sometimes I don't. It's never personal. 💚