> pin a core of my cpu at 100% and consume half a gig of ram...
I'm not doubting you, and I acknowledge that I hear that kind of thing with some frequency, but I've not seen Slack (running in Chrome on Ubuntu) use anything like those amounts of resources.
I've had a pretty busy slack client running for several days, and it's using 204,484K of memory and 2.0% of one CPU.