I'm fine with Windows, as long as you disable the Microsoft account and don't look much at the start menu it mostly gets out of the way, and doesn't have UI latency.
Teams, on the other hand, is an UI nightmare:
- It has noticeable UI latency even in the best computers.
- If you open a document within it, there is no way (that I know of) to get back to the chat to discuss something about the document, and then back to the document again. Once you go to a chat, the document is closed and you have to navigate the whole file system to find it again, click it, and wait for several seconds for it to open because lag.
- If you search for messages with a given word, it shows you a list of the messages but it doesn't allow you to click on each to look at the context, which is what I want to do like 99% of the time I search for a message in a chat app.
- If you have it set up to launch on startup, it will open private conversations and again, take a couple of seconds to close even if you're a fast clicker, because of its ubiquitous lag. Incredibly inconvenient if you use the laptop to give a presentation (of course I know that I can just set it to not open on startup, but I shouldn't need to do that. It makes sense to have it on startup 99% of the time as I almost always use it, just don't open a private chat and stick it in front of the screen with focus as the first thing you do!).
- The filesystem is a nightmare (not only Teams' fault, but the whole Office ecosystem): files associated to a team, vs. files on someone's OneDrive, vs. SharePoint. After 2 years of using it, I still don't get the difference between OneDrive and SharePoint and I'm still not able to find anything without stumbling around, and I'm supposed to be a tech guy.
- Sometimes you drag a file on a chat to send it to the other person and it makes you explicitly set permissions (using a laggy UI, of course) so the other person can access the file. Why would I send a file to a private chat if I didn't want to show it to the other person?
- Calls don't scale. Quality degrades fast.
- Sometimes a "team" will go bold for no reason. I click on it, and there is nothing new. Or a chat window will go blank and only come back when someone types a new message.
Mind you, it has good things (I like the simplicity of partially typing a few names in the search box, having it autocomplete, click on the people and starting a group chat, for example) but the UI is a dumpster fire. I'm not anti-Microsoft as a whole (I like Windows, and kind of like Excel) and while I kind of tolerate it, there are plenty of reasons to get angry with it. And some of the issues above (like search not showing context, rendering it all but useless) are really basic, I don't know how they could even pass QA.