If it's just infra management you want, then use Hipchat. It does the same things Slack does, at $2/user/mo instead of $8. Slack is ridiculously expensive.

It's only expensive compared to HipChat which is a subsidised gateway service that leads to Jira. Our company used HipChat for about a year before moving to Slack. Honestly, the differences are not many and any reasonable team could choose either.

I think we migrated to Slack for connectivity reasons, fonts and general user interface, and the bigger list of integrations. Are these worth $6 per user per month? If you've got the money then maybe. But it's by no means a given.

And that's what I meant by "among other things".

Originally, we were using Campfire.

As needs grew beyond just putting out fires, we looked at Hipchat, Flowdock, and Slack. We probably would have gone with Hipchat (because of the price), if they had SSO, or better JIRA integration. Slack had both.