IMO discord is way better.

Pretty interface, easy to use, voice is pretty low latency (although I miss my mumble server), and it uses ~80mb of ram to sit in like 5 groups, which while not fantastic blows "rather open it in chrome" slack out of the water.

New signal desktop instantly uses 200mb and has to "loading messages" for 3s every single startup :(

It's not buggy for you? The tab on the left is always glitching out on me, and things just simply don't work like they should, whether I'm using Firefox or Chrome. It incorrectly says "<so and so> is typing..." when the person is typing in a different subchat.

On the whole, for a product proudly marketing itself as a Slack replacement, it does a terrible job actually providing the same functionality.

In what way is Slack better?

It just always works for me, and I've run into all sorts of annoying cases where Discord doesn't do what it's supposed to, especially in the browser.

Slack's extra features and integrations are nice, too, but I just don't like Discord because it... doesn't even work as advertised.