I made a test with PL and ON1 noise reduction.
Image is from: Nikon D850 Sample Images | Photography Blog
Loaded in ON1 22.5 and PL 5.4
quick and dirty grading to get a slightly flat image and to let the image look similar in PL and ON1 (I was suprised how different the processing results of PL and ON1 are at default settings).
Screenshots taken from XnView image viewer set to sRGB and 100% (I am watching on an sRGB calibrated monitor).
Export to tiff with NR switched off in develop settings:
Interesting: The ON1 image looks like there is croma NR going on even though NR is switched off.
Cross check: Classic HQ NR in dxo activated, croma set to 80, all other options to 0.
Now dxo and ON1 images look similar again.
dxo DeepPrime and ON1 NoNoise at default settings:
For me at default settings this is a win for ON1. DXO has less noise but lost way to much detail. On the other hand, for me ON1 is overdoing the sharpening / detail preservation.
Edit: First conclusion: For me DeepPrime and ON1 at default settings are both not suitable for this image.
DeepPrime (+ some quick n’ dirty unsharp mask) and NoNoise at custom settings:
Edit: (check also the third batch: there I use Lens Sharpness not Unsharp Mask which I think gives better results)
Both are great. Is there a “winner” for me? Not really.
One note though about editing.
The result of the unsharp mask depends heavily on the result of DeepPrime (if there is noise, the unsharp might increase it). So one need to judge the result of the unsharp mask in the tiny DeepPrime preview. For me this was a challange. In the end I had to do exports to get an impression of the result. I would prefer to have a feature to at least make the preview bigger (even at the cost of longer preview processing time). ON1 is better in this regard because it shows the NoNoise in the normal edit window.
On the other hand for me dxo runs way smoother and quicker than ON1 (tested on notebook, Core i7 10th gen, 16GB, RTX 2070-maxQ with 8GB vram).