If one prefers smoothing the image at the expense of details, then additional noise reduction is easy to apply in Picture Window Pro, “free for personal or commercial use”. The results come close to the Topaz AI results.
Starting with Photolab’s PRIME resullts presented earlier, I experimented with PWP’s noise reduction tool embedded in the advanced sharpening transformation.
In the noise reduction tab, adjust the desired blurring radius and the spatial frequency range where to apply the blurring. This transformation is very poweful; it also includes despecking and sharpening – both of which I have not enabled for this experiment.