The company I was with earlier this year was using it. They used the free version which was fine for them (no long term storage of history.) Had PagerDuty hooks that send notices in when something would bork in production. Then just the plain usage of the apps across all platforms was just ... Easy. Which is saying a lot. No real learning curve to use it. Its reminds me of ICQ, but with current geek hacking expectations.
- CW