After the last post comparing Darktable and Lightroom in terms of noise reduction I went back and did more testing. I'm not sure why I never really tried the setting the HSV lightness mask to the wavelets mode before but I gave it a try and managed what I consider better results for this shot. Look for yourself below.

Wavelets VS Non-local Means

Settings for Wavelets on Left, Right for NLM

Just for comparison here is the Lightroom 5 output.

Adjusting the transparency on the HSV Lightness mask down a bit helped with the ugly pattern and sharpened things up a bit too.

This just goes to show that it pays to try new things. Having this many options available is a bit of a double edge sword. If one chooses to really get in there and tweak things Darktable can produce exemplary images. However, this comes at a steeper learning curve and hit in editing time. Lightroom and ACR in general does a lot behind the scenes where as I'm finding Darktable to me more of a chose your own adventure deal. There's no such things as free lunch.