For every kind of team sysops work I've ever done, I would say that Slack is indeed the best available tool.
Not every organization needs this kind of workflow though, so the best available tool depends on what your organization has to integrate. (Disclosure: I've never tried HipChat.)
Not every organization needs this kind of workflow though, so the best available tool depends on what your organization has to integrate. (Disclosure: I've never tried HipChat.)