I prefer the way Slack groups threaded conversations within a channel. Teams channels are clunky enough that we just end up using group chats instead.

Literally every week I encounter new bugs, it gets worse and worse. Many very basic features (like inline code with back ticks) just stopped working months ago and don't work anymore. Scrolling in some channels is completely broken, jumping around wildly. Sometimes messages just don't get sent (both on Android & Web). Sometimes calls work perfectly all day, then the next call just randomly changes audio device settings and I have to find what's wrong again. Sometimes the video stream of a shared screen just doesn't work, or stops working when switching to the small pop-up window while looking at chats, so the other person has to re-share. Sometimes the "available" state is just broken and keeps getting set to "away". The search just doesn't find many things, even when searching with fairly exact parameters.

It's a daily source of frustration & literally gets worse by the week. I can't remember a program that's made me angry as much as Teams has.

Notification syncing between devices is nonexistent in Teams and there are no conversation threads.

In general teams is way more buggy with worse UX. I don't know if it's a thing on Teams that our workplace disabled, but there's no decent notification management. If I take a day off, I can set my notifications in Slack as mute for that day and I can manage notifications for messages vs mentions vs mute per channel.

On Teams I can't permanently set Enter as new line, I have to click that rich text editor icon for every single message.
On mobile Teams started doing this thing in group chats where, if I move the cursor with drag on space gesture and then move it back to the end of the message, Teams interprets this as a desire to "attach a program", like power apps (whatever that is).
Pasting in code block also gets me every time. I'll start a code block in Teams window, go to another window, copy the text and click back on my code block. Teams just drops the cursor to the end of message outside my code block and by the time I notice I already hit ctrl+v.

My last pet peeve is about formatted copy pasting and applies to Slack as well but Teams having more text formatting options shows more of an impact. Never, and I repeat, NEVER have I wanted to paste anything with formatting, especially if I grabbed it form a website, word, excel, pdf or a code editor. Why is it the default and nonnegotiable? I can change the default on Libre Office, why not on Teams? It's a chat app why would I need headings like in a regular doc?
Every time it gets me, ctrl+c, ctrl+v, fuck ctrl+z, ctrl+shift+v…

On a 4k monitor you can still only get about 80 characters of monospaced font per line, because of the "negative space" fetish UX designers have.

Something dead simple like posting a stack trace, and then having someone able to, you know, read it... It's just not something teams really does well.

I can understand how the tooling probably does a ton of stuff that corporate users want (integrating with calendars, tons of access controls for spaces for important people to talk, etc) but for a dev working primarily with a handful of other devs and qas, there is a feature set mismatch. I can't begin to tell you how badly I don't give a shit about 99% of its features.

Teams is trash, I have to use it with certain clients, slack for everything else. Literally everything it does is like a wish.com fail version of slack. Like if you ordered slack on temu.

They are now finally putting some work in to improve it. I don’t remember much what I used to hate particularly, it was mostly UI related, bugs or the bad Mac implementation.

The new combined view with chats and teams is much better than the split sections.

It took them until just recently to have a basic code block format like everyone else, instead of this annoying editor-in-editor mess they had before (and still kept for some reason).

It used to be very buggy like you had to hunt down the source of some notification to mark it as read. It still doesn’t 100% sync with Outlook. If an event is cancelled and I click delete in Outlook, I also have to go to Teams and „read“ this update. You can set group events in Teams but they somehow don’t end up in Outlook.

What I really like are the clay-like emojis designs.

Do you really use Teams? If you do, you should not be able to say that