It's nice to hear of other people with a similar stack on HN (Azure, PowerShell, TeamCity, HipChat, and presumably C#/.NET)! It's working well for us too.

In addition, we're increasingly doing more with ChatOps with mmbot (as an Azure Web Job): https://github.com/mmbot/mmbot

One nice thing about mmbot is that if you use the DLL mode instead of the CSX mode, you get a great IDE debugging experience which makes it even faster to create meaningful ChatOps extensions. I've found it to be a more pleasant development experience that Hubot with CoffeeScript.