Noise Ninja - Why don't I use this more often?

I purchased Noise Ninja several months ago, but never spent much time with it. I dusted it off tonight, and now I'm wondering why it doesn't have a fixed spot in my photography workflow.

I need to read up on the science and techniques of noise removal to understand better how to use Noise Ninja, but after 5 minutes of basically just using their automatic settings, I was able to clean up this ISO6400 shot from earlier this year.

Click the following to see the difference (open in new windows)

Original:


After Noise Ninja: