I showed a Nik HDR Efex Pro processed ice cave the other day and wanted to balance that with a couple of Photomatix Pro HDRs.
Both images started in Lightroom where I processed the components. My workflow includes removing any of the default settings in the Develop Module that effect tonality. From top to bottom I do the following: Blacks-0, Brightness-0, Contrast-0, Tone Curve's Point Curve-Linear, Detail's Sharpening Amount-0, and Lens Correction to remove vignetting and chromatic aberration. I will warn you here, after you make those adjustments the components will not look good.
You can easily make a Preset and the process goes much quicker.
Once the image returns from Photomatix I will go through my normal optimization workflow. This often returns the above sliders and options to near their default.
In the case of these two images, I processed them twice in Photomatix, adjusted in Lightroom, and then combined the two in Photoshop. For the interior shot I also used Topaz Detail to add some shape and form.