Slack also has a nicer UI and better integrations for us, and generally just always works how I want. I don't know if I'd call it a "revelation", but it's way better than any comparable product I've used.
[0] - I think HipChat recently added support for more granular notification settings, but I don't use it anymore. Also, it took over 3 years of this being their 1st or 2nd most requested feature before they addressed it, so I don't give them any credit for having it now.
[1] - They might get an email depending on their settings, but the HipChat app would never give a notification.