I don't keep the client running all the time, but i do get notifications when I'm mentioned by name; haven't noticed any egregious problems.

I don't think Hipchat is a POS - it gets the job done - but it is lacking some features that I would consider to be fairly basic. (Why can't I edit messages except with the s// syntax? Why can't I do basic text formatting?)

I do agree with you on the lack of faith, though. Jira's text formatting is even worse than Hipchat's.