Atom and Slack don't "feel" normal to me, they feel sluggish. They also take up a lot of resources (CPU, RAM). With what I'm running on a daily basis, I need all the resources I can get.
I think lpsz said it best, "It's cool for developers. It's not cool for the users". I'd qualify that with "It's cool for web developers".
Atom hovers at less than 5% usage between at least 5 separate workers for me. It's no 'ed' in terms of RAM but if it's under a gig it's fine by me. Certainly better than IntelliJ was in that respect.
Works pretty perfectly with rust as well. I have both a vim and an atom rust setup and they have near total feature parity.
I think lpsz said it best, "It's cool for developers. It's not cool for the users". I'd qualify that with "It's cool for web developers".