Curious: I've always used slack from a web browser rather than their native app. What, if anything, do you personally miss from the web app in slack?
The main reason I kept the desktop app, is so that I don't need to "download" the app every time my browser's cached copy is invalidated or expires. But being able to start the app with a couple keystrokes from my OS's quick launch menu is also nice.
I guess it's too early for me to evaluate the performance of Twist, because I am not on any large teams there. But I can see that Slack at least, has room for improvement in rendering performance. Perhaps there is some general optimization they are missing out on, like immutable state + shouldComponentUpdate. That one saved a flailing app of mine in the past.
I'm in Firefox on Linux, i7-4500U, 8GB ram.