We used it for several years after our needs outgrew IRC. From the cloud version starting in 2013, we migrated to the hosted version in 2016, and it was a pretty painless migration and not too hard to manage/update. I think it stuck around for several years after that until the parent org moved everyone over to Slack Enterprise.

HipChat felt like a great featureset-to-complexity ratio. All-in-all good memories :)