Teams is also pretty snappy for the first month or so. But once you use it for about 8 months, it's just so painfully slow; it will take multiple seconds to switch channel. I suspect it's because they use sqlite under the hood for storing messages and have some bad queries or bad indexes.
If you are using the mobile app then just lol. You'll always be seen as "away" even if actively engaging in discussions, and you'll be thinking you're caught in a time-trap with regards to accuracy of statuses and messages.
And my final rant is the pathetic conflation of "team" and "channel" nomenclature. The fuck is wrong with just calling them channels?