Not just UX.. one day Element just wouldn't connect anymore (and in a typical webapp fashion, no useful error messages). Nuking its config directory and starting from scratch fixed it (never needed to do that in 20 years of using irssi).

I've seen other issues like video previews getting their bottom half completely crippled. Can't make a video call just sharing the desktop with someone -- it demands a microphone. Can't disable read markers that are broadcast to everyone (bad for privacy imo). They were working on this when I looked into it but I've no idea if they've fixed it yet.

And yes I've seen UX bugs such as some UI setting getting stuck in a state when you try to toggle it in the settings.

I'm guessing these are more Element issues rather than Matrix issues (except for the read markers). But I get the vibe that we won't be seeing a client I like anytime soon; or it'll be a very minimalistic client with no support for all the fancy modern features, in which case I'd likely get the same or better experience with IRC anyway.