Obviously subjective but since comments mention UI: I love the web/desktop UI. It's got great power user features including well designed keyboard shortcuts. https://zulip.com/help/keyboard-shortcuts for details (my favorite is "n" for "next topic", which I use every morning to catch up on conversations).

n for next topic, j and k to move up and down within a topic, + to add a thumbs up to the current post, : to add any other emoji, and t to get a list of Recent topics so you can decide which ones to catch up on first. All these make Zulip so pleasant and breezy to use.

Plus it's fast, Slack is a vat of molasses and I hate my life every time I have to use it.

To me, the UI is unfriendly/confusing. Not sure if I'm just used to Slack, but it is very hard to use.

Simple things like stream messages only being displayed halfway down the viewport with no scrollbar making it seem like there are no earlier messages.

I've never used it. What's wrong with it?

I loved most of it, but (1) the search feature, specially for non English language, rely on postgres tokenized search which is worse than slack. (2) there is no "gallery view" for all files shared with a group or a person. (3) The mobile app had different render from the web.. and bad RTL render (4) slack bots compatibility sometimes miss the mark..

Other than that... It worked fine. I kinda liked it but slack is more robust for me (even if slow).

On the search front, have you tried the PGroonga search backend?

https://zulip.readthedocs.io/en/latest/subsystems/full-text-...

(It's only available when self-hosting at present.)

UI is not great.

First time I used it, it was a bit confusing, as I didn't really know what to expect. Is it email? Live chat? A forum?

Turns out, it's a bit of both, and trying to use it as any single one of them, will probably make it harder to use.

Basically, I treat it as a live chat where it's easier to participate in different topics at the same time, Slack on steroids where everything is a "Thread" basically.

Sounds similar to Flowdock model? I greatly preferred that and was so disappointed when Slack finally rolled out their version of threading. It felt almost useless in comparison.

Alas, Flowdock is dead now and I've learned to embrace Slack as the better remaining alternative over Teams or Google Chat.

That’s what the grandparent comment said, what specifically do you find wrong with the UI? I for one really enjoy it and the keyboard shortcuts.

I think it's better than slacks sidebar threaded reply. It also has better code blocks, less irritating pop up magic and no bots nagging you to fill in credentials all the time.

Yeah the UI make me feel like it was designed by developers. Which is cool if you love a clunky utilitarian vibe. :)