Our small team at work uses hipchat instead. But it is a matter of what we work on if we login at all on a given day. Getting close to going live with a release and we are on. Otherwise most are not logged in.

I have slack open all day for a non profit, a regional developers group and a product user group. The regional developer's group is 95% noise and after following it for 3 weeks zero value for me. Think I will quit that one.