As is always the case, I was about the furthest away from thinking about computers when I realised that I had made some stupid decision WRT the logic in vstsBuildWatcher. So in between kicking a ball around my living room with The Boy (and causing very little damage in the process) I spent the afternoon uodating the vstsBuildWatcher Module. I've pushed the changes out to GitHub and PowerShell Gallery.
The major change is that by default both successful and failed builds are monitored, and you have to explicitly filter only failed builds by including the “-showFailedOnly” flag. I've updated the readme to reflect this change.