Unreliable service, buggy clients

Reliability is ridiculously bad. I've used dozens of consumer and enterprise chat services, and hipchat is by far the worst in terms of performance (latency) and reliability (uptime).

The osx and android clients are horrendously buggy and poorly designed. It regularly drops typed and submitted messages; they are unable to handle a network change or packet drop of any kind (the network layer should be rewritten from scratch). The search function is terrible and breaks every few months. The web client is ok.